epoprostenol

Prostacyclin (PGI 2 ) possesses various physiological functions, including modulation of nociception, inflammation and cardiovascular activity. Elucidation of these functions has been hampered by the absence of selective IP receptor antagonists. ... Two structurally distinct ...

Purpose: To describe a unique prostacyclin dosing regimen utilized to treat a case of secondary Raynaud's phenomenon and summarize the existing literature on parenteral prostacyclin use for Raynaud's phenomenon in adult patients. Summary: A 54-year-old female was admitted for initiation of continuous intravenous infusion epoprostenol to treat secondary Raynaud's phenomenon which failed to respond to nifedipine and sildenafil. The infusion was titrated to a target dose of 9 ng/kg/min for 5 days. Upon completion of treatment, improvements in the patient's pain, range of motion, and digital perfusion were observed. Sustained improvements were noted seven weeks later. Parenteral prostacyclins may therefore be considered for Raynaud's phenomenon which fails to respond to conventional therapies. Epoprostenol has previously been used to treat Raynaud's phenomenon mainly in the form of intermittent, intravenous infusions. There are logistical concerns associated with the use of a continuous infusion prostacyclin which should be addressed before this therapy is chosen. Conclusion: This case highlights a successful outcome in a patient with secondary Raynaud's phenomenon treated with a 5-day continuous infusion of epoprostenol. It is reasonable to consider this treatment regimen in patients with secondary Raynaud's phenomenon in whom other treatments have failed.

IGF binding protein-related protein 1 (IGFBP-rP1) is highly expressed in the rat uterus around the time of implantation. In the present study, we determined the periimplantation localization of IGFBP-rP1 mRNA and assessed the effects of recombinant IGFBP-rP1 on the proliferative and prostacyclin (PGI 2)-producing abilities of cultured endometrial cells early in pregnancy. IGFBP-rP1 mRNA was detected at high levels in endometrial stromal cells close to the smooth muscle of interimplantation sites around the time of implantation but absent from decidual zones surrounding the embryo. Differential uterine IGFBP-rP1 expression was also recognized in the delayed implanting pregnant model, but the level of mRNA decreased as decidual tissues formed in the decidualization model. Recombinant IGFBP-rP1 inhibited the proliferation of endometrial stromal cells in vitro and arrested them in the G 1 phase of the cell cycle. Furthermore, IGFBP-rP1 significantly stimulated PGI 2 synthesis and cyclooxygenase II mRNA expression in myometrial cells, both of which are essential molecules for successful implantation. These data suggest that IGFBP-rP1 is an implantation-associated protein and that it modulates the proliferation of rat uterine cells and their production of PGI 2 during the periimplantation period. (Endocrinology 145: 5243-5251, 2004)

A model for gastric mucosal injury is proposed in which a key pathogenetic event is the disruption in the normal relationships among several circadian rhythms of gastric function. In the rat a circadian rhythm in acid secretion was found to be out of phase with a circadian rhythm in gastric pepsin secretion, another aggressive factor, and several mucosal defensive factors (mucus and bicarbonate efflux and tissue prostacyclin content). Gastric corpus mucosal blood flow circadian patterns paralleled the rhythmicity in acid secretion and, therefore, was out of phase with the other measured mucosal defensive factors. Thus, gastric mucosal defense was maintained by different mechanisms over the 24-hr cycle. During the dark phase, when this species was active and when acid secretion was highest, enhanced damage by topical acidified aspirin was documented, despite increased mucosal blood flow. Natural asynchrony in circadian rhythms of gastric function can be protective of gastric mucosal integrity but disruption of this circadian interplay of gastric aggressive and defensive factors could theoretically lead to greater vulnerability to damage. In the human, a circadian rhythm in basal gastric acidity has been described but no information exists as to the possibility of similar rhythmic variation in other gastric factors (aggressive and defensive) and possible disruption of these rhythms in disease.

The effects of prostaglandin E2 (PGE2), PGF2,, and PGO2 and of inhibitors of prostaglandin synthesis and action, on the K+-evoked [3H]-noradrenaline ([3H]-NA) overflow from rat cerebral cortex slices have been investigated. 2 PGE2 reduced, while indomethacin (a prostaglandin synthesis inhibitor) or SC 19220 (a prostaglandin receptor antagonist) increased, the evoked overflow compared with controls. 3 The inhibition of [3H]-NA overflow by PGE2 was dose-dependently antagonized by SC 19220. 4 The results indicate that PGE2 modulates NA release in rat cerebral cortex in vitro.

Chronic kidney disease (CKD) is public health concern even in Asian countries. TRK-100STP, a sustained release tablet of an orally-active prostacyclin analogue, beraprost sodium, is suggested to suppress worsening of some parameters of renal filtration function, containing in slope of 1/serum creatinine (1/SCr) vs. time in a phase II clinical trial. We describe the design of the phase IIb/III trial of TRK-100STP, CASSIOPEIR (CRF Asian Study with Oral PGI2 derivative for Evaluating Improvement of Renal function) conducted in approximately 160 centers in China, Hong Kong, Japan, Malaysia, Republic of Korea, Taiwan, and Thailand. A total of 750 patients (n = 250 per group) with primary glomerular disease or nephrosclerosis were planned to be enrolled. Patients were randomized into one of three treatment groups in a double-bind, placebo-controlled manner: TRK-100STP 60 μg b.i.d.; TRK-100STP 120 μg b.i.d.; or placebo. The treatment period is planned to last 2 to 4 years. The primary effi...

A model for gastric mucosal injury is proposed in which a key pathogenetic event is the disruption in the normal relationships among several circadian rhythms of gastric function. In the rat a circadian rhythm in acid secretion was found to be out of phase with a circadian rhythm in gastric pepsin secretion, another aggressive factor, and several mucosal defensive factors (mucus and bicarbonate efflux and tissue prostacyclin content). Gastric corpus mucosal blood flow circadian patterns paralleled the rhythmicity in acid secretion and, therefore, was out of phase with the other measured mucosal defensive factors. Thus, gastric mucosal defense was maintained by different mechanisms over the 24-hr cycle. During the dark phase, when this species was active and when acid secretion was highest, enhanced damage by topical acidified aspirin was documented, despite increased mucosal blood flow. Natural asynchrony in circadian rhythms of gastric function can be protective of gastric mucosal integrity but disruption of this circadian interplay of gastric aggressive and defensive factors could theoretically lead to greater vulnerability to damage. In the human, a circadian rhythm in basal gastric acidity has been described but no information exists as to the possibility of similar rhythmic variation in other gastric factors (aggressive and defensive) and possible disruption of these rhythms in disease.

The endothelium controls the tone of the underlying vascular smooth muscle mainly through the production of vasodilator mediators. In some cases, this function is hampered by the release of constrictor substances. The endothelial mediators are also involved in the regulation by the endothelium of vascular architecture and the blood cell-vascular wall interactions. The endothelium-derived factors comprise nitric oxide (NO), prostacyclin, and a still unknown endothelium-derived hyperpolarizing factor(s) (EDHF). In most vascular diseases, the vasodilator function of the endothelium is attenuated. In advanced atherosclerotic lesions, endothelium-dependent vasodilatation may even be abolished. Various degrees and forms of endothelial dysfunction exist, including (1) the impairment of G i proteins, (2) less release of NO, prostacyclin and/or EDHF, (3) increased release of endoperoxides, (4) increased production of reactive oxygen species, (5) increased generation of endothelin-1, and (6) decreased sensitivity of the vascular smooth muscle to NO, prostacyclin and/or EDHF. The levels of bradykinin and angiotensin II within the vascular wall are controlled by angiotensin-converting enzyme (ACE). ACE degrades bradykinin and generates angiotensin II. Bradykinin stimulates endothelial cells to release vasodilators. The actions of the kinin are maintained despite endothelial dysfunction, except in very severe arterial lesions. Angiotensin II may be in part responsible for endothelial dysfunction because it induces resistance to the vasodilaor action of NO. Thus, impairment of the generation of angiotensin II blocks the direct and indirect vasoconstrictor effect of the peptide. By potentiating bradykinin, ACE inhibitors promote the release of relaxing vasodilator mediators to restore vasodilator function, and to prevent platelet aggregation as well as the recruitment of leukocytes to the vascular wall.

This is a critical abstract of an economic evaluation that meets the criteria for inclusion on NHS EED. Each abstract contains a brief summary of the methods, the results and conclusions followed by a detailed critical assessment on the reliability of the study and the conclusions drawn.

To analyze ischemia-reperfusion effects on the cerebrovascular adrenergic response, the left middle cerebral artery (MCA) of anesthetized goats was occluded for 120 min and reperfused for 60 min. Isolated segments from the left (ischemic) and right (control) MCA exhibited isometric constriction in response to noradrenaline (10 − 8-10 − 4 M, in the presence of β-adrenoceptors blockade), phenylephrine (α 1-adrenoceptors agonist, 10 − 8-10 − 4 M), B-HT-920 (α 2-adrenoceptors agonist, 10 − 7-3 × 10 − 3 M) or tyramine (indirect sympatheticomimetic amine, 10 − 8-10 − 4 M), but this constriction was greater in ischemic arteries. The cyclooxygenase (COX) inhibitor meclofenamate (10 − 5 M) augmented the response to noradrenaline only in control arteries. The prostacyclin (PGI 2) synthesis inhibitor tranylcypromine (TCP, 10 − 5 M) increased the response to noradrenaline in control arteries and reduced it in ischemic arteries. The thromboxane A 2 (TXA 2) synthase inhibitor furegrelate (10 − 6 M) did not modify the noradrenaline effect in both types of arteries, whereas the TXA 2 receptor antagonist SQ 29 548 (10 − 5 M) and the COX-2 inhibitor NS-398 (10 − 6 M) decreased the response to noradrenaline only in ischemic arteries. PGI 2 caused a small relaxation in control arteries and a small contraction in ischemic arteries. α-Adrenoceptors and COX-2 protein expression and the metabolite of PGI 2 were augmented in ischemic arteries. Therefore, ischemia-reperfusion may increase the cerebrovascular responsiveness to noradrenaline, through upregulation of α-adrenoceptors and increased COX-2-derived PGI 2 exerting a vasoconstrictor action. After ischemiareperfusion, noradrenaline might increase PGI 2 production thus contributing to adrenergic vasoconstriction and/or PGI 2 would potentiate the noradrenaline effects.

An episode of gastroenteritis triggered severe necrosis of all extremities in a previously asymptomatic male. Hepatic and renal involvement were also manifest, while the hematological picture was one of thrombotic microangiopathic hemolytic anemia. Antiphospholipid antibodies were negative. He responded well to a combination of plasma exchange, anticoagulation (heparin), parenteral steroids, and antibiotics, as well as vasodilators (prostacycline) and hyperbaric oxygen, but died because of a cerebral hemorrhage. The differential diagnosis included thrombotic thrombocytopenic purpura/hemolytic-uremic syndrome, or seronegative catastrophic antiphospholipid (Asherson's) syndrome. The dangers of administering such a combination of therapies with anticoagulation, as well as vasodilatation (prostacycline) and hyperbaric oxygen, are highlighted by the case report and emphasized.

The hvpotensive action of captopril and ena1ap;'il is not prostacyclin dep&dent Angiotensin converting enzyme inhibitors have been proposed to have a prostaglandin-dependent component to their hypotensive action. The aim of this study was to assess whether the structurally dissimilar angiotensin converting enzyme inhibitors captopril and enalapril stimulate the synthesis of prostacyclin, whether their hypotensive action is blunted by indomethacin, and whether these biochemical or physiologic parameters differ for the two drugs, in white subjects with essential hypertension. Twelve patients were enrolled and 11 finished the study. The study consisted of a double blind, randomized, double-crossover design. All patients received either placebo or 50 mg indomethacin twice a day for 3 weeks; after 1 week of placebo or indomethacin either 50 mg captopril or 10 mg enalapril twice a day was added and continued for 2 weeks. Each patient received every possible combination. Neither captopril nor enalapril stimulated prostacyclin production as determined by measurement of the urinary excretion rate of its main enzymatic metabolite, 2,3-dinor-6-keto-pro~tagIandinF~~. Although indomethacin reduced the urinary excretion of the enzymatic metabolite of prostacyclin by more than 50%, it did not influence the hypotensive effect of captopril or enalapril. We conclude that neither captopril nor enalapril have a significant prostacyclin-dependent component to their hypotensive action.

Abstra&-CC& induced cellular injury and its modification by prostacyclin (PGI,) was studied in cultured rat hepatocytes. Biosynthesis of both intracellular and serum proteins and that of phospholipids decreased upon CC& treatments (IC, 7.0, 2.5 and 3.2 mM, respectively). After 1 hr exposure of the cells to CC.&, the reductions in the biosynthesis increased further with time. PGI, treatments (W5-10mp M) of the hepatocytes subsequent to CC& poisoning resulted in partial recovery from the cell injury evaluated at the fifth hour of the experiment. Optimal effects of PGIr were found at a concentration of 1O-7-1O-8 M, while higher and lower concentrations offered less protection. Upon the addition of Ccl4 a higher catabolic rate of PIP2 and an increased formation of inositol phosphates were observed. This alteration was shown to precede the defects in the labelling of the major phospholipid components.

Although histamine plays an essential role in inflammation, its influence on cyclooxygenases (COX) and prostanoid homeostasis is not well understood. In this study, we investigated the effects of histamine on the expression of COX-1 and COX-2 and determined their contribution to the production of PGE 2 , prostacyclin (PGI 2), and thromboxane A 2 in human coronary artery endothelial cells (HCAEC). Incubation of HCAEC monolayers with histamine resulted in marked increases in the expression of COX-2 and production of PGI 2 and PGE 2 with no significant change in the expression of COX-1. Histamine-induced increases in PGI 2 and PGE 2 production were due to increased expression and function of COX-2 because gene silencing by small interfering RNA or inhibition of the catalytic activity by a COX-2 inhibitor blocked prostanoid production. The effects of histamine on COX-2 expression and prostanoid production were mediated through H 1 receptors. In addition to the direct effect, histamine was found to amplify LPS-stimulated COX-2 expression and PGE 2 and PGI 2 production. In contrast, histamine did not stimulate thromboxane A 2 production in resting or LPS-activated HCAEC. Histamine-induced increases in the production of PGE 2 and PGI 2 were associated with increased expression of mRNA encoding PGE 2 and PGI 2 synthases. The physiological role of histamine on the regulation of COX-2 expression in the vasculature is indicated by the findings that the expression of COX-2 mRNA, but not COX-1 mRNA, was markedly reduced in the aortic tissues of histidine decarboxylase null mice. Thus, histamine plays an important role in the regulation of COX-2 expression and prostanoid homeostasis in vascular endothelium.

The effect of age, dietary fat type and all-rac-alpha-tocopheryl acetate (vitamin E) supplementation on ex vivo synthesis of lung eicosanoids was measured in C57BL/6NIA mice using a 2 (age) x 3 (fat) x 3 (vitamin E) factorial design. Young (3-mo-old) and old (24-mo-old) mice were fed a semipurified diet containing 5% (by wt) corn oil, coconut oil or fish oil supplemented with 30, 100 or 500 mg vitamin E/kg for 4 wk. Ex vivo synthesis of thromboxane B2 (TXB2) and 6-keto-prostaglandin F1 alpha (PGI2) were measured by RIA in lung homogenates. Old mice had significantly higher concentrations of TXB2 and PGI2 than did young mice, resulting in a significant increase in the TXB2:PGI2 ratio with aging. Young and old mice fed fish oil had significantly lower concentrations of PGI2 and TXB2 than those fed corn oil or coconut oil. The degree of reduction varied according to age and vitamin E status. Old mice fed fish oil and 30 mg vitamin E/kg diet had the lowest plasma vitamin E concentration...

Kidney stones can be very painful, but they rarely evolve into a life-threatening situation. This was not the case for a 44-year-old woman known to have renal calculus in the distal left ureter. She presented to the emergency department with severe flank pain. On arrival, she became severely hypotensive (blood pressure, 50/30 mm Hg; heart rate, 140 beats per minute). Fluids were administered, and she stabilized after intubation and mechanical ventilation. Amoxicillin/clavulanate and ciprofloxacin were administered intravenously. Blood tests at this time demonstrated a white blood cell count of 13.7 ϫ 10 3 mm 3 , hemoglobin of 12g/dL, and a platelet count of 122,000/mm 3. Ultrasound disclosed mild left hydronephrosis with a small amount of reactive perirenal fluid. No renal calculus was identified on computed tomography, but 2 urethral stents were inserted. The patient's blood pressure dropped a second time. At that point, she was transferred to the intensive care unit for treatment of urosepsis and septic shock.

The present study was designed to evaluate, P2026 [(2-((2-(nitrooxy)ethyl)disulfanyl)ethyl 2-(2-(2,6dichlorophenylamino)phenyl)acetate)], a novel NO (nitric oxide) donor prodrug of diclofenac for its ability to release NO and diclofenac, and whether P2026 provides advantage of improved activity/gastric tolerability over diclofenac. Oral bioavailability of P2026 was estimated from plasma concentration of diclofenac and nitrate/nitrite (NOx). Antiinflammatory activity was evaluated in three different models of inflammation: acute (carrageenan-induced paw oedema), chronic (adjuvant-induced arthritis), and systemic (lipopolysaccharide-induced endotoxic shock). Gastric tolerability was evaluated from compound's propensity to cause gastric ulcers. P2026 exhibited dose-dependent diclofenac and NOx release. Similar to diclofenac, P2026 showed potent anti-inflammatory activity in acute and chronic model, whereas it improved activity in systemic model. Both diclofenac and P2026 inhibited gastric prostaglandin, but only diclofenac produced dose-dependent haemorrhagic ulcers. Thus, the results suggest that coupling of NO and diclofenac contribute to improved gastric tolerability while retaining the anti-inflammatory properties of diclofenac.

Introduction: Treprostinil diethanolamine is an innovative salt form of the prostacyclin analogue, treprostinil sodium, developed as an oral sustained release (SR) osmotic tablet. The availability of a formulation permitting convenient systemic delivery might have applicability to scleroderma vascular complications. We evaluated pharmacokinetics and perfusion in scleroderma patients with digital ischemia following escalating twice-daily doses of treprostinil diethanolamine SR. Methods: Scleroderma patients with digital ulcers were enrolled in this dual-center, open-label, phase I pharmacokinetic study. Drug concentrations and perfusion, quantified by laser Doppler imaging, were measured over 12 hours at the 2 mg and 4 mg (or maximally tolerated) doses. Pharmacokinetic parameters were determined from individual plasma concentration versus time profiles using non-compartmental analysis methods. Digital perfusion and skin temperature were modeled as a function of log-transformed drug concentration and other covariates by performing repeated measures analyses using random effects models. Results: Nineteen scleroderma patients (84% female, 53% limited scleroderma) received treprostinil diethanolamine SR with dose titration up to 4 mg twice daily as tolerated. Peak concentrations (mean maximum plasma concentration (C max) = 1,176 and 2,107 pg/mL) occurred approximately 3.6 hours after dose administration, and overall exposure (under the plasma concentration-time curve from time 0 to 12 hours post dose (AUC 0-12) = 7,187 and 12,992 hr*pg/mL) was linear between the 2 mg and 4 mg doses. Perfusion and digital skin temperature were positively associated with log-transformed plasma concentration at the 4 mg dose (P = 0.015 and P = 0.013, respectively). The most frequent adverse events were similar to those seen with prostacyclin analogues. Conclusions: Oral treprostinil diethanolamine was effectively absorbed in patients with scleroderma. Drug administration was temporally associated with improved cutaneous perfusion and temperature. Treprostinil diethanolamine may provide a new therapeutic option for Raynaud's phenomenon and the peripheral vascular disease of scleroderma. Trial registration: ClinicalTrials.gov NCT00848939.

This study assessed the efficacy and safety of inhaled treprostinil in pulmonary arterial hypertension (PAH) patients receiving therapy with either bosentan or sildenafil. Background There is no cure for PAH, despite effective treatments, and outcomes remain suboptimal. The addition of inhaled treprostinil, a long-acting prostacyclin analog, might be a safe and effective treatment addition to other PAH-specific oral therapies. Methods Two hundred thirty-five PAH patients with New York Heart Association (NYHA) functional class III (98%) or IV symptoms and a 6-min walk distance (6MWD) of 200 to 450 m while treated with bosentan (70%) or sildenafil were randomized to inhaled treprostinil (up to 54 g) or inhaled placebo 4 times daily. The primary end point was peak 6MWD at 12 weeks. Secondary end points included time to clinical worsening, Borg Dyspnea Score, NYHA functional class, 12-week trough 6MWD, 6-week peak 6MWD, quality of life, and PAH signs and symptoms. The biomarker N-terminal pro-brain natriuretic peptide (NT-proBNP) was assessed. Results Twenty-three patients withdrew from the study prematurely (13 treprostinil, 10 placebo). The Hodges-Lehmann between-treatment median difference in change from baseline in peak 6MWD was 19 m at week 6 (p ϭ 0.0001) and 20 m at week 12 (p ϭ 0.0004). Hodges-Lehmann between-treatment median difference in change from baseline in trough 6MWD at week 12 was 14 m (p ϭ 0.0066). Quality of life measures and NT-proBNP improved on active therapy. There were no improvements in other secondary end points, including time to clinical worsening, Borg Dyspnea Score, NYHA functional class, and PAH signs and symptoms. Inhaled treprostinil was safe and well-tolerated. Conclusions This trial demonstrates that, among PAH patients who remain symptomatic on bosentan or sildenafil, inhaled treprostinil improves exercise capacity and quality of life and is safe and well-tolerated. (TRIUMPH I: Double Blind Placebo Controlled Clinical Investigation Into the Efficacy and Tolerability of Inhaled Treprostinil Sodium in

The action of PGE1, PGE2, PGI2 and iloprost on superoxide anion generation, lysosomal enzyme release, and changes of Ca2+ fluxes in human polymorphonuclear leukocytes (PMN) was studied in vitro. Both PGE-type compounds were equipotent inhibitors of FMLP-and PAF-stimulated superoxide anion generation, ß-glucuronidase release (IC50 3–5 µmol/l) and Ca2+ influx while PGI2 and iloprost were ineffective at concentrations up to 10

Various laboratories have reported that local subcutaneous or subdermal injection of VEGF165 at the time of surgery effectively attenuated ischemic necrosis in rat skin flaps, but the mechanism was not studied and enhanced angiogenesis was implicated. In the present study, we used the clinically relevant isolated perfused 6 × 16-cm pig buttock skin flap model to 1) test our hypothesis that VEGF165 is a potent vasodilator and acute VEGF165 treatment increases skin perfusion; and 2) investigate the mechanism of VEGF165-induced skin vasorelaxation. We observed that VEGF165 (5 × 10–16–5 × 10–11 M) elicited a concentration-dependent decrease in perfusion pressure (i.e., vasorelaxation) in skin flaps preconstricted with a submaximal concentration of norepinephrine (NE), endothelin-1, or U-46619. The VEGF165-induced skin vasorelaxation was confirmed using a dermofluorometry technique for assessment of skin perfusion. The vasorelaxation potency of VEGF165 in NE-preconstricted skin flaps (pD...

Epoprostenol (prostacyclin) is a potent inhibitor of platelet aggregation and causes relaxation of vascular smooth muscle. These effects may be beneficial in patients with acute myocardial infarction. The effect of epoprostenol infusion in patients with acute myocardial infarction was evaluated in a randomised double blind study of 45 patients with evidence of myocardial infarction of < 16 hours' duration. The patients were given a 72 hour infusion of epoprostenol (23) or placebo (22). The maximum dose was 5 ng/kg/min. The mean time to treatment was 8 3 hours (range 3-8-15 9 hours). The mean dose was 4 9 ng/kg/min. The patients were followed until day 30. No significant differences were found between the groups in mortality, development of congestive heart failure, cardiogenic shock, arrhythmias, recurrent chest pain, reinfarction, peak creatine kinase concentration, or the time taken to attain peak creatine kinase concentration. No significant difference in baseline ejection fraction was noted between groups, and no significant change in ejection fraction occurred within each group or between groups. The only significant side effect was the development of facial flushing in the epoprostenol group.

Eicosanoids are important vascular regulators, but the phospholipase A2 (PLA2) isoforms supporting their production within the cardiovascular system are not fully understood. To address this, we have studied platelets, endothelial cells, and leukocytes from 2 siblings with a homozygous loss-of-function mutation in group IVA cytosolic phospholipase A2 (cPLA2α). Chromatography/mass spectrometry was used to determine levels of a broad range of eicosanoids produced by isolated vascular cells, and in plasma and urine. Eicosanoid release data were paired with studies of cellular function. Absence of cPLA2α almost abolished eicosanoid synthesis in platelets (e.g., thromboxane A2, control 20.5 ± 1.4 ng/ml vs. patient 0.1 ng/ml) and leukocytes [e.g., prostaglandin E2 (PGE2), control 21.9 ± 7.4 ng/ml vs. patient 1.9 ng/ml], and this was associated with impaired platelet activation and enhanced inflammatory responses. cPLA2α-deficient endothelial cells showed reduced, but not absent, formation...

The effect of haemorrhagic hypotension on the levels of prostaglandin Ez (POEz), thromboxane Bz (TXBz)' and 6-keto prostaglandin Fla (6-keto-POFla) in cortical tissue of rats was studied. Lightly anesthetized rats were subjected to steady-state hypotension for 15 min, with a mean arterial blood pressure of 80, 60, and 40 mm Hg, and compared to a control group of normo

Objective: Elevated levels of 11-dehydrothromboxane B 2 (11-dehydro-TXB 2) excreted in urine have been observed in acute ischemic stroke. This marker of platelet activation has not been investigated in patients with acute spontaneous intracerebral hemorrhage (ICH). Methods: We examined 43 patients with spontaneous ICH and 23 controls. Urinary excretion rates of 11-dehydro-TXB 2 , 2,3-dinorthromboxane B 2 (2,3 dinor-TXB 2) and 2,3-dinor-6-ketoprostaglandin F 1a (2,3-dinor-PGF 1a) during the first week and at 3 months after ICH were compared between patients who had or had not used aspirin and controls. Results: On admission, ICH patients without aspirin use had significantly higher urinary levels of 11-dehydro-TXB 2 (pb0.001), 2,3-dinor-TXB 2 (pb0.001) and 2,3-dinor-PGF 1a (p=0.019) than controls. Aspirin users had significantly lower urinary levels of these metabolites than nonusers. The metabolite levels of aspirin users on admission did not significantly differ from those of controls. The differences between aspirin users and nonusers leveled off during the following 3-5 days, however, as the blocking

Epidemiological and clinical studies indicate that vitamin E may reduce the risk of cardiovascular disease (CVD). Modulation of adhesion molecule expression and chemokine production by vitamin E may contribute to its beneficial effect. In this study we found that the enrichment of confluent human aortic endothelial cells (HAEC) or U937 monocytic cells with increasing doses of vitamin E (d-a-tocopherol, 20, 40, and 60 mmol/l for 20 h) inhibited their adhesion when either or both cell types were stimulated with interleukin (IL)-1b. Enrichment of HAEC with the same doses of vitamin E suppressed IL-1b-stimulated expression of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and endothelial leukocyte adhesion molecule-1 (E-selectin). Supplementation with increasing doses of vitamin E up to 60 mmol/l was not effective in preventing spontaneous production of monocyte chemoattractant protein-1 (MCP-1), but supplementation with vitamin E at 60 mmol/l reduced IL-8 production significantly. However, IL-1b-induced productions of both MCP-1 and IL-8 were dose-dependently suppressed by enrichment of cells with vitamin E. Vitamin E, at the doses used, did not significantly change the spontaneous production but dose-dependently inhibited the IL-1b-induced production of inflammatory cytokine IL-6. We concluded that vitamin E could inhibit production of chemokines and inflammatory cytokines, in addition to inhibiting adhesion of HAEC to monocytes by reducing expression of adhesion molecules when cells were activated with an inflammatory cytokine. These mediators are actively involved in the pathogenesis of atherosclerosis. Therefore, their inhibition by vitamin E may contribute to vitamin E's reported reduction in risk of CVD.

Importance: Pulmonary hypertension (PH) is a fatal disease. Although the prognosis of pulmonary arterial hypertension (PAH) has improved with targeted therapies, the outcome is dependent on early detection and an accurate diagnosis. Objective: To determine the accuracy of PH diagnoses in patients referred to PH centers and the frequency of PAH-specific medication use despite an uncertain or incorrect diagnosis. Design: Multicenter, descriptive, cross-sectional study. During a 10-month period in 2010 and 2011, data on newly referred patients were collected and entered into a secure Internet database. Setting: Three large tertiary PH centers. Participants: One hundred forty consecutive patients newly referred to PH centers were invited to participate, and all consented to do so. Results: Of 140 patients referred with a mean age of 56 years, 95 (68%) were referred by cardiologists or pulmonologists and 86 (61%) had disease classified as World Health Organization functional class III or IV. Fifty-six of the prereferral diagnoses (40%) were PAH, 42 (30%)

RS-93427, a novel analog of prostacyclin, increased adenylate cyclase activity in human platelet membranes (EC50 = 42 nM) to approximately the same maximum level as that produced by prostacyclin (EC50 = 87 nM). The concentration-response curve for RS-93427 appeared to be monophasic. However, a selective prostaglandin D2 antagonist (BW A868C) significantly reduced the stimulation of adenylate cyclase produced by low concentrations of RS-93427 (3.2 to 32 nM). RS-93520, a stereoisomer of RS-93427, also stimulated adenylate cyclase activity but in a biphasic pattern. BW A868C reduced the activation produced by low concentrations of RS-93520 with a 100-fold shift in the response curve. Maximum stimulation by RS-93520 (4.5-fold) was less than that obtained with prostaglandin D2 (7.3-fold). Thus, the stimulation of adenylate cyclase activity by low concentrations of RS-93520 is due to an interaction with prostaglandin D2 receptors while the activation by RS-93427 is mediated by both prostacyclin and prostaglandin D2 receptors. Additional data in support of these conclusions was obtained when these prostaglandins were tested as inhibitors of ADP-induced platelet aggregation in the presence or absence of BW A868C. The potent stimulation of prostaglandin receptors with chimeric molecules provides some insight into the structural features required for receptor activation.

Supplementary key words cyclooxygenase-pathway • prostaglandin I-synthase • prostacyclin-synthase • prostacyclin • smooth muscle cells • endothelial cells Hypoxia is the underlying condition in several human pathologies, including cardiovascular diseases, chronic renal disease, hematological and pulmonary disorders, and cancer (1). It triggers adaptive mechanisms aimed to increase local oxygen concentration to insure cell viability, and it is critical driving tissue remodeling (2, 3). In fact, hypoxia regulates a large number of genes involved in widespread biological activities, including regulation of vascular function, cell metabolism, cell survival, and cell growth and motility. The transcriptional response to hypoxia is mediated by a network of transcription factors (4-9), but particularly by the hypoxia-inducible factor (HIF). HIF-1, the prototype of this family, is a heterodimeric basic helixloop-helix transcription factor composed of HIF-1 ␤ (constitutive subunit) and HIF-1 ␣ (oxygen-sensitive subunit) (10). In recent years, a growing number of genes potentially regulated by hypoxia have been identifi ed (11). Nevertheless, the global picture of genes and proteins regulated by hypoxia in vascular cells is not completely understood. Increasing evidence emphasizes the role of a prostanoid biosynthetic pathway in hypoxia-mediated biological effects. In several cell types, hypoxia upregulates the inducible Abstract Hypoxia affects vascular function and cell metabolism, survival, growth, and motility; these processes are partially regulated by prostanoids. We analyzed the effect of hypoxia and infl ammation on key enzymes involved in prostanoid biosynthesis in human vascular cells. In human vascular smooth muscle cells (VSMC), hypoxia and interleukin (IL)-1 ␤ synergistically increased prostaglandin (PG)I 2 but not PGE 2 release, thereby increasing the PGI 2 /PGE 2 ratio. Concomitantly, these stimuli upregulated cyclooxygenase-2 (COX-2) expression (mRNA and protein) and COX activity. Interestingly, hypoxia enhanced PGI-synthase (PGIS) expression and activity in VSMC and human endothelial cells. Hypoxia did not signifi cantly modify the inducible microsomal-PGE-synthase (mPGES)-1. Hypoxia-inducible factor (HIF)-1 ␣-silencing abrogated hypoxia-induced PGIS upregulation. PGIS transcriptional activity was enhanced by hypoxia; however, the minimal PGIS promoter responsive to hypoxia (-131 bp) did not contain any putative hypoxia response element (HRE), suggesting that HIF-1 does not directly drive PGIS transcription. Serial deletion and sitedirected mutagenesis studies suggested several transcription factors participate cooperatively. Plasma levels of the stable metabolite of PGI 2 and PGIS expression in several tissues were also upregulated in mice exposed to hypoxia. These data suggest that PGIS upregulation is part of the adaptive response of vascular cells to hypoxic stress and could play a role in counteracting the deleterious effect of infl ammatory stimuli.

We have investigated the regulatory role of PGll and its stable analogs, i.e., iloprost and cicaprost, on IZ(S)-HETE-and TPA-enhanced tumor cell integrin expression and adhesion. Walker 256 carcinosarcoma cells express allbp3 integrin receptors, which mediate their adhesion to endothelium, subendothelial matrix and fibronectin. Adhesion is enhanced by treatment with exogenous IZ(S)-HETE but not IZ(R)-HETE or other lipoxygenase-derived hydroxy fatty acids, as well as by TPA. Both II(S)-HETE and TPA enhanced cullbp3 expression on W256 cells. PGlz iloprost and cicaprost inhibited both I2(S)-HETE-and TPA-enhanced adhesion to endothelium and subendothelial matrix as well as dlbp3 expression on W256 cells. The mechanism responsible for the effect of PGI, was explored. Prostacyclin treatment of W256 cells resulted in an enhanced production of CAMP in a time-and dose-dependent manner. Pre-treatment of tumor cells with increasing concentrations of adenosine resulted in a dose-dependent decrease in the PGl, effect on TPA or I2(S)-HETE-enhanced adhesion, suggesting that the PGI, effect is mediated through PKA. Dibutyryl CAMP also blocked the I2(S)-HETE-or TPA-enhanced adhesion, and adenosine pre-treatment did not result in an inhibition of the dibutyryl CAMP effect. Collectively, our results suggest that the cyclooxygenase metabolite PGIZ can antagonize the lipoxygenase metabolite I 2(S)-HETE-and TPA-enhanced allbf33 expression and tumor cell adhesion via activation of adenylate cyclase and elevation of intracellular levels of CAMP.

The aim of the study was to determine the mechanism of the hypotension and bradycardia produced by prostacyclin (PGI2). 2 Haemodynamic studies were carried out in nineteen open-chest beagle dogs anaesthetized with chloralose. PGI2 was infused intravenously or into the left atrium. 3 Infusions of PGI2 either intravenously or into the left atrium equally reduced arterial pressure and total peripheral resistance but bradycardia was greater after infusion into the left atrium. 4 Comparison of effects of PGI2 with those of prostaglandin E2 (PGE2) showed that although left atrial infusions both reduced aortic pressure and total peripheral resistance, PGE2 always increased heart rate, cardiac output and maximum acceleration. 5 Similar effects were observed with sodium nitroprusside except that it always caused tachycardia and reduced stroke volume. 6 Atropine (0.05 or 1 mg/kg i.v.) reduced or reversed the bradycardia induced by PGI2 but its hypotensive effects were reduced only after 1 mg/kg atropine. After vagotomy changes in cardiac output, stroke volume and maximum acceleration were increased, the hypotensive effects of PG12 were reduced and the bradycardia was reversed; effects induced by PGE2 were not significantly altered. 7 The hypotension induced by prostacyclin is due to two components, a direct relaxation of vascular smooth muscle and a reflex, non-cholinergic vasodilatation. The bradycardia is reflex in nature and is partially mediated by the vagus pathway.

Abstra&-CC& induced cellular injury and its modification by prostacyclin (PGI,) was studied in cultured rat hepatocytes. Biosynthesis of both intracellular and serum proteins and that of phospholipids decreased upon CC& treatments (IC, 7.0, 2.5 and 3.2 mM, respectively). After 1 hr exposure of the cells to CC.&, the reductions in the biosynthesis increased further with time. PGI, treatments (W5-10mp M) of the hepatocytes subsequent to CC& poisoning resulted in partial recovery from the cell injury evaluated at the fifth hour of the experiment. Optimal effects of PGIr were found at a concentration of 1O-7-1O-8 M, while higher and lower concentrations offered less protection. Upon the addition of Ccl4 a higher catabolic rate of PIP2 and an increased formation of inositol phosphates were observed. This alteration was shown to precede the defects in the labelling of the major phospholipid components.

Objectives: In order to evaluate the effect of a medical administration for the sudden deafness patients, single-drug treatment for idiopathic sudden sensorineural hearing loss (ISSHL) was assessed at multi-centers participating in the Acute Severe Hearing Loss Study Group sponsored by the Ministry of Health, Labor and Welfare of Japan. Methods : The subjects consisted of ISSHL patients who were (1) 20 years of age or older, (2) diagnosed within 2 weeks after the onset of hearing loss, (3) showing a mean hearing level of 40 Á/90 dB at five frequencies from 250 to 4000 Hz, (4) previously untreated, and (5) with normal for age in hearing of the opposite ear. The drugs used in this study were ATP, alprostadil, hydrocortisone and amidotrizoate, which were administered intravenously, and beraprost sodium and betamethasone, which were given orally. Two drugs were assigned to each center, one of which was selected according to the code hidden in envelopes and administered for 1 week. The treatment after the single-drug administration was conducted at the discretion of each center. The hearing gain and recovery rate at 1 week after the initiation of single-drug treatment and at 1 month or over when the hearing level was fixed, were evaluated based on the criteria for hearing recovery

Allergic airway diseases are immune disorders associated with heightened type 2 immune responses and IL-5 and IL-13 production at the site of inflammation. We have previously reported that cyclooxygenase (COX) inhibition by indomethacin augmented allergic airway inflammation in a STAT6-independent manner. However, the key COX product(s) responsible for restraining indomethacin-mediated STAT6-independent allergic inflammation is unknown. In this study, using the mouse model of OVA-induced allergic airway inflammation, we identified that PGI2 receptor (IP) signaling was critical for indomethacin-induced, STAT6-independent proallergic effects. We demonstrated that IP deficiency increased inflammatory cell infiltration, eosinophilia, and IL-5 and IL-13 expression in the lung in a STAT6-independent manner. The augmented STAT6-independent allergic inflammation correlated with enhanced primary immune responses to allergic sensitization and elevated production of multiple inflammatory chemo...

Prostacyclin (PGI2) contributes to the maintenance of a nonadhesive luminal surface in blood vessels due to its anti‐platelet and vasodilatory properties. Here, we sought to determine whether peripheral blood lymphocytes (PBL) may regulate the PGI2 production of human umbilical vein endothelial cells (HUVEC). Cell‐cell contact between HUVEC and lymphocytes markedly enhanced PGI2 synthesis as a function of the number of lymphocytes added. This stimulated synthesis was totally suppressed when lymphocytes and HUVEC were separated by a microporous insert. It was not due to prostaglandin H synthase up‐regulation. The pretreatment of lymphocytes with the PGI2 synthase inhibitor tranylcypromine partially inhibited PGI2 synthesis (47%), suggesting a transcellular metabolism of the endothelial prostaglandin endoperoxide PGH2 by the lymphocyte PGI2 synthase. Experiments using [14C]arachidonate‐labeled lymphocytes coincubated with unlabeled HUVEC, and [14C]arachidonate‐labeled HUVEC coincubate...

Poly(ADP-ribose) polymerase (PARP) plays an important role in ischaemic cell death, and 3-aminobenzamide (3-AB), one of the PARP inhibitors, has a protective effect on ischaemic stroke. We investigated the neuroprotective mechanisms of 3-AB in ischaemic stroke. The occlusion of middle cerebral artery (MCA) was made in 170 Sprague-Dawley rats, and reperfusion was performed 2 h after the occlusion. Another 10 Sprague-Dawley rats were used for sham operation. 3-AB was administered to 85 rats 10 min before the occlusion [3-AB group (n = 85) vs. control group without 3-AB (n = 85)]. Infarct volume and water content were measured, brain magnetic resonance imaging, terminal deoxynucleotidyltransferase (TdT)-mediated dUTP-biotin nick end-labelling (TUNEL) and Cresyl violet staining were performed, and immunoreactivities (IRs) of poly(ADP-ribose) polymer (PAR), cleaved caspase-3, CD11b, intercellular adhesion molecule-1 (ICAM-1), cyclooxygenase-2 (COX-2), phospho-Akt (pAkt) and phospho-glycogen synthase kinase-3 (pGSK-3) were compared in the peri-infarcted region of the 3-AB group and its corresponding ischaemic region of the control group at 2, 8, 24 and 72 h after the occlusion. In the 3-AB group, the infarct volume and the water content were decreased (about 45% and 3.6%, respectively, at 24 h), the number of TUNEL-positive cells was decreased (about 36% at 24 h), and the IRs of PAR, cleaved caspase-3, CD11b, ICAM-1 and COX-2 were significantly reduced, while the IRs of pAkt and pGSK-3 were increased. These results suggest that 3-AB treatment could reduce the infarct volume by reducing ischaemic cell death, its related inflammation and increasing survival signals. The inhibition of PARP could be another potential neuroprotective strategy in ischaemic stroke.

Basal and acetylcholine-stimulated PGI 2 release was progressively diminished as a function of diminishing oxygen tension (pO 2 from approximately 165 to 25 mm.Hg). The basal and stimulated production of other prostanoids, thromboxane A 2 , PGF 2 alpha and PGE 2 , was also ...

Isolated pancreatic islets of the rat were either prelabeled with [3H]arachidonic acid, or were incubated over the short term with the concomitant addition of radiolabeled arachidonic acid and a stimulatory concentration of glucose (17mM) for prostaglandin (PG) analysis. In prelabeled islets, radiolabel in 6-keto-PGFl~ , PGE2, and 15-keto-13,14-dihydro-PGF2~ increased in response to a 5 min glucose (17mM) challenge. In islets not prelabeled with arachidonic acid, label incorporation in 6-keto-PGFl~ increased, whereas label in PGE 2 decreased during a 5 min glucose stimulation; after 30-45 min of glucose stimulation labeled PGE levels increased compared to control (2.8mM glucose) levels. Enhanced labelling of PGF2~ was not detected in glucose-stimulated islets prelabeled or not. Isotope dilution with endogenous arachidonic acid probably occurs early in the stimulus response in islets not prelabeled. D-Galactose (17mM) or 2-deoxy-glucose (17mM) did not alter PG production. Indomethacin inhibited islet PG turnover and potentiated glucose-stimulated insulin release. Islets also converted the endoperoxide [3H]PGH2 to 6-keto-PGFl~ , PGF2~ , PGE 2 and PGD 2, in a tlme-dependent manner and in proportions similar to arachidonic acid-derived PGs. In dispersed islet cells, the calcium ionophore ionomycin, but not glucose, enhanced the production of labeled PGs from arachidonic acid. Insulin release paralled PG production in dispersed cells, however, indomethacin did not inhibit ionomycinstimulated insulin release, suggesting that PG synthesis was not required for secretion. In confirmation of islet PGI 2 turnover indicated by 6-keto-PGFle production, islet cell PGl2-1ike products inhibited platelet aggregation induced by ADP. These results suggest that biosynthesis of specific PGs early in the glucose secretion response may play a modulatory role in islet hormone secretion, and that different pools of cellular arachidonic acid may contribute to PG biosynthesis in the microenvironment of the islet. iPortions of this work were performed in partial fulfillment of the requirements for the Degree of Doctor of Philosophy. 2To whom to address reprint requests.