Papers by Jose Antunes-Rodrigues
Molecular Brain, Jan 7, 2016
Background: Rasd1 is a member of the Ras family of monomeric G proteins that was first identified... more Background: Rasd1 is a member of the Ras family of monomeric G proteins that was first identified as a dexamethasone inducible gene in the pituitary corticotroph cell line AtT20. Using microarrays we previously identified increased Rasd1 mRNA expression in the rat supraoptic nucleus (SON) and paraventricular nucleus (PVN) of the hypothalamus in response to increased plasma osmolality provoked by fluid deprivation and salt loading. RASD1 has been shown to inhibit adenylyl cyclase activity in vitro resulting in the inhibition of the cAMP-PKA-CREB signaling pathway. Therefore, we tested the hypothesis that RASD1 may inhibit cAMP stimulated gene expression in the brain.
Cellular and Molecular Neurobiology, Apr 16, 2021
The renin-angiotensin system (RAS) is involved in cardiovascular and hydroelectrolytic control, b... more The renin-angiotensin system (RAS) is involved in cardiovascular and hydroelectrolytic control, being associated with the development of hypertension. The restraint stress (RS) model is an aversive situation, which promotes a sustained increase in blood pressure and heart rate, and stimulation of the hypothalamic–pituitary–adrenal axis. Stress leads to an increase of angiotensin-II contents both in the circulation and the central nervous system (CNS), as well as an increased expression of AT-1 receptors in CNS structures related to stress. Stressful stimuli are associated with the modulation of autonomic nervous system, as well as baroreflex; changes in this adjustment mechanism are related to cardiovascular diseases. We hypothesized that RAS is involved in the modulation of autonomic, neuroendocrine, and functional RS-caused alterations. The intravenous (i.v) pretreatment of rats with lisinopril, an angiotensin-converting-enzyme inhibitor, reduced the RS-evoked pressor response. The doses of 0.1 and 0.3 mg/kg also reduced the RS-evoked tachycardia, while in the dose of 1 mg/kg of lisinopril potentiated the tachycardic one. Additionally, i.v. pretreatment with losartan, a selective AT-1 receptor antagonist, reduced the pressor and the tachycardic responses caused by RS. Pretreatment with lisinopril 0.3 mg/kg increased the power of the low frequency (LF) band of the systolic BP spectrum after the treatment without affecting this parameter during RS. The pretreatment with losartan 1 mg/kg increased the power of the high frequency (HF) band and reduced the LF (n.u.) and the LF/HF ratio of the pulse interval spectrum in the first hour of RS. Concerning baroreflex sensitiveness (SBR), pretreatments with losartan or lisinopril did not affect the gain of the baroreflex sequences. However, the pretreatment with losartan reduced the baroreflex effectiveness index of the total sequences in the third hour of the RS. These results indicate that Ang-II, via the AT-1 receptor, plays a facilitating influence on the cardiovascular response caused by RS; facilitates sympathetic activation and reduces parasympathetic activity related to RS; facilitates the baroreflex activation during RS and favors corticosterone release under this stress model. The impairment of Ang-II synthesis, as well as the blockade of AT-1 receptors, may constitute an important pharmacological strategy to treat cardiovascular consequences caused by stress.
Journal of the Endocrine Society, 2020
POMC neurons expressed in the ARC are essential for energy balance and glucose homeostasis. It ha... more POMC neurons expressed in the ARC are essential for energy balance and glucose homeostasis. It has been suggested the involvement of these neurons in the control of endocrine axes, such as the HPA. During fasting, POMCARC neurons are silenced as an effort to reduce body weight loss and to avoid hypoglycemia. During this process glucocorticoid secretion and activation of enzymes involved in the hepatic gluconeogenesis take place in order to preserve the homeostasis. In this study, to clarify the contribution of POMCARC neurons to the adaptive changes in energy homeostasis, glucose metabolism and HPA axis activity induced by food deprivation we used DREADDs to specifically activate POMCARC. Bilateral injections of the AAV carrying the excitatory DREADD (hM3DGq) or only the reporter gene (mCherry) have been performed into the ARC of Pomc-ires-cre and WT mice. Two weeks later the animals were fasted for 36hr, treated with saline (5 i.p. injections each 8hrs) and blood samples were colle...
Rev. odontol. Univ. …, 1991
Brazilian Journal of Medical and Biological Research, 2022
Hypovolemia induced by hemorrhage is a common clinical complication, which stimulates vasopressin... more Hypovolemia induced by hemorrhage is a common clinical complication, which stimulates vasopressin (AVP) secretion by the neurohypophysis in order to retain body water and maintain blood pressure. To evaluate the role of brain L-glutamate and angiotensin II on AVP secretion induced by hypovolemia we induced hemorrhage (B25% of blood volume) after intracerebroventricular (icv) administration of AP5, NBQX, or losartan, which are NMDA, AMPA, and AT1 receptor antagonists, respectively. Hemorrhage significantly increased plasma AVP levels in all groups. The icv injection of AP5 did not change AVP secretion in response to hemorrhage. Conversely, icv administration of both NBQX and losartan significantly decreased plasma AVP levels after hemorrhage. Therefore, the blockade of AMPA and AT1 receptors impaired AVP secretion in response to hemorrhage, suggesting that L-glutamate and angiotensin II acted in these receptors to increase AVP secretion in response to hemorrhage-induced hypovolemia.
The FASEB Journal, Apr 1, 2018
Fractalkine (FKN; CX3CL1) belongs to the gamma-chemokine family and binds to CX3CR1 receptors. Cu... more Fractalkine (FKN; CX3CL1) belongs to the gamma-chemokine family and binds to CX3CR1 receptors. Currently, the mechanisms involving FKN-induced inflammatory mediators are research targets in an atte...
Journal of Developmental Origins of Health and Disease, Feb 6, 2019
The mechanisms involved in kidney disturbances during development, induced by vitamin D3 deficien... more The mechanisms involved in kidney disturbances during development, induced by vitamin D3 deficiency in female rats, that persist into adulthood were evaluated in this study. Female offspring from mothers fed normal (control group, n=8) or vitamin D-deficient (Vit.D-, n=10) diets were used. Three-month-old rats had their systolic blood pressure (SBP) measured and their blood and urine sampled to quantify vitamin D3 (Vit.D3), creatinine, Na+, Ca+2 and angiotensin II (ANGII) levels. The kidneys were then removed for nitric oxide (NO) quantification and immunohistochemical studies. Vit.D- pups showed higher SBP and plasma ANGII levels in adulthood (P<0.05) as well as decreased urine osmolality associated with increases in urinary volume (P<0.05). Decreased expression of JG12 (renal cortex and glomeruli) and synaptopodin (glomeruli) as well as reduced renal NO was also observed (P<0.05). These findings showed that renal disturbances in development in pups from Vit.D- mothers observed in adulthood may be related to the development of angiogenesis, NO and ANGII alterations.
Frontiers in Endocrinology
The important involvement of the suprachiasmatic nucleus (SCN) and the activity of vasopressinerg... more The important involvement of the suprachiasmatic nucleus (SCN) and the activity of vasopressinergic neurons in maintaining the rhythmicity of the female reproductive system depends on the mRNA transcription-translation feedback loops. Therefore, circadian clock function, like most physiological processes, is involved in the events that determine reproductive aging. This study describes the change of mRNA expression of clock genes, Per2, Bmal1, and Rev-erbα, in the hypothalamus-pituitary-gonadal axis (HPG) of female rats with regular cycle (RC) and irregular cycle (IC), and the vasopressinergic neurons activity in the SCN and kisspeptin neurons in the arcuate nucleus (ARC) of these animals. Results for gonadotropins and the cFos/AVP-ir neurons in the SCN of IC were higher, but kisspeptin-ir was minor. Change in the temporal synchrony of the clock system in the HPG axis, during the period prior to the cessation of ovulatory cycles, was identified. The analysis of mRNA for Per2, Bmal1,...
Aging is a complex biological process, with gradual and progressive decline in structure and func... more Aging is a complex biological process, with gradual and progressive decline in structure and function in many organ systems. Our objective is to determine if structural changes produced by aging, vary with sex, in a stressful situation such as dehydration. The expression of Slc12a3 mRNA in renal cortex, α-smooth muscle actin (α-SMA) and fibronectin, was evaluated in male and female rats aged 3 and 18 months submitted or not to water deprivation (WD) for 48 hours. When comparing ages, 18-month-old males showed lower expression of Slc12a3 mRNA than 3-month-old males, and control and WD 18-moth-old male and female rats exhibited higher expression of α-SMA than respective 3-month-old rats. Fibronectin was higher in both control and WD 18-month-old males than respective 3-month-old males. In females, only control 18-month-old rats showed higher fibronectin than control 3-month-old rats. When we compared sex, control and WD 3-month-old female rats had lower expression of Slc12a3 mRNA than...
Scientific Reports
Sodium appetite is a motivational state involving homeostatic behavior, seeking the ingest of sal... more Sodium appetite is a motivational state involving homeostatic behavior, seeking the ingest of salty substances after sodium loss. There is a temporal dissociation between sodium depletion (SD) and the appearance of sodium appetite. However, the responsible mechanisms for this delay remain poorly elucidated. In the present study, we measured the temporal changes at two and 24 h after SD in the gene expression of key elements within excitatory, inhibitory, and sensory areas implicated in the signaling pathways involved in the onset of sodium appetite. In SD rats, we observed that the expression of critical components within the brain control circuit of sodium appetite, including Angiotensin-type-1 receptor (Agtr1a), Oxytocin-(OXT-NP)-neurophysin-I, and serotonergic-(5HT)-type-2c receptor (Htr2c) were modulated by SD, regardless of time. However, we observed reduced phosphorylation of mitogen-activated protein kinases (MAPK) at the paraventricular nucleus (PVN) and increased oxytocin r...
Frontiers in Physiology, 2018
It is known that circulating angiotensin II (ANG-II) acts on the circumventricular organs (CVOs),... more It is known that circulating angiotensin II (ANG-II) acts on the circumventricular organs (CVOs), which partially lack a normal blood-brain barrier, to stimulate pressor responses, vasopressin (AVP), and oxytocin (OT) secretion, as well as sodium and water intake. Although ANG-II type 1 receptors (AT1 R) are expressed in neurons and astrocytes, the involvement of CVOs glial cells in the neuroendocrine, cardiovascular and behavioral responses induced by central ANG II remains to be further elucidated. To address this question, we performed a set of experiments combining in vitro studies in primary hypothalamic astrocyte cells (HACc) and in vivo intracerebroventricular (icv) microinjections into the lateral ventricle of awake rats. Our results showed that ANG-II decreased glutamate uptake in HACc. In addition, in vivo studies showed that fluorocitrate (FCt), a reversible glial inhibitor, increased OT secretion and mean arterial pressure (MAP) and decreased breathing at rest. Furthermore, previous FCt decreased AVP secretion and sodium intake induced by central ANG-II. Together, our findings support that CVOs glial cells are important in mediating neuroendocrine and cardiorespiratory functions, as well as central ANG-II-induced AVP release and salt-intake behavior in awake rats. In the light of our in vitro studies, we propose that these mechanisms are, at least in part, by ANG-II-induced astrocyte mediate reduction in glutamate extracellular clearance.
Hypertension Research, 2020
Vasopressin (VP) is a neurohypophyseal peptide best known for its role in maintaining osmotic and... more Vasopressin (VP) is a neurohypophyseal peptide best known for its role in maintaining osmotic and cardiovascular homeostasis. The main sources of VP are the supraoptic and paraventricular (PVN) nuclei of the hypothalamus, which co-express the vasopressin V1a and V1b receptors (V1aR and V1bR). Here we investigate the level of expression of VP and VP receptors in the PVN of borderline hypertensive rats (BHRs), a key integrative nucleus in neuroendocrine cardiovascular control. Experiments were performed in male BHRs and Wistar rats (WR) equipped with radiotelemetry device for continuous hemodynamic recordings, under baseline conditions and after saline load without or with stress. The autonomic control of the circulation was evaluated by spectral analysis of blood pressure (BP) and heart rate (HR) variability and baro-receptor reflex sensitivity (BRS) using the sequence method. Plasma VP was determined by radioimmunoassay, and VP, V1aR and V1bR gene expression by RT-qPCR. Under baseline conditions, BHRs had higher BP, lower HR and enhanced BRS in respect to WRs. BP and HR variability was unchanged. In the PVN, overexpression of VP and V1bRs genes were found and plasma VP was increased. Saline load downregulated V1bR mRNA without affecting VP mRNA expression, plasma VP and the BP. Adding stress increased BP, BP and HR low frequency sympathetic spectral markers, decreased plasma VP without altering the level of expression of VP and VP receptors in PVN. It follows that overexpression of VP and V1bR in the PVN is a characteristic trait of BHR, and that sympathetic hyperactivity underlies stressinduced hypertension.
Journal of the Endocrine Society, 2020
Female gonadal hormones, especially 17β-estradiol (E2), are known to mediate hydromineral homeost... more Female gonadal hormones, especially 17β-estradiol (E2), are known to mediate hydromineral homeostasis and blood pressure mainly by attenuating renin-angiotensin system (RAS) actions. The RAS plays an essential role in the maintenance of hydromineral and cardiovascular homeostasis via angiotensin II (ANGII), a key component of the RAS. However, the cellular mechanisms of the interaction between E2 and ANGII and its physiological role are not fully elucidated. Recently, our group showed that ERK1/2 is involved in sodium intake and vasopressin release induced by ANGII in female rats. In addition, E2 decreases ERK1/2 phosphorylation induced by ANGII in the hypothalamus and in structures of the lamina terminalis (LT). Thus, the goal of the present study was evaluated some mechanisms that could be involved in ERK1/2 dephosphorylation induced by E2 in response to ANGII, such as MAPK phosphatase 1 (MKP-1) and GRK5. For this, Wistar female rats (~250g) were submitted to ovariectomy and on th...
Frontiers in Pharmacology, 2020
We hypothesized that dorsomedial hypothalamus (DMH) modulates autonomic and neuroendocrine respon... more We hypothesized that dorsomedial hypothalamus (DMH) modulates autonomic and neuroendocrine responses in rats at rest and when subjected to restraint stress (RS). Male Wistar rats were used, and guide cannulas were bilaterally implanted in the DMH for microinjection of vehicle or the nonspecific synaptic blocker CoCl 2 (1 mM/100 nl). A polyethylene catheter was inserted into the femoral artery for the recording of arterial pressure and heart rate (HR). Tail temperature was measured using a thermal camera. The session of RS started 10 min after DMH treatment with vehicle or CoCl2. Under homecage condition, the pretreatment of DMH with CoCl 2 increased baseline blood pressure (BP), and heart rate (HR) without affecting the tail temperature. In addition, it decreased plasma vasopressin levels without affecting plasma corticosterone and oxytocin contents. When rats pretreated with CoCl 2 were exposed to RS, the RS-evoked cardiovascular were similar to those observed in vehicle-treated animals; however, because cobalt pretreatment of the DMH increased baseline BP and HR values, and the RS-evoked cardiovascular responses did not exceed those observed in vehicle-treated animals, suggesting a possible celling limit, the possibility that DMH is involved in the modulation of RS-evoked cardiovascular responses cannot be certainly excluded. Nonetheless, the pretreatment of DMH with CoCl 2 blocked the reduction in tail temperature caused by RS. The DMH pretreatment with CoCl 2 did not modify the RS-evoked increase in plasma corticosterone and oxytocin contents. In conclusion, the present data suggest the involvement of DMH in the maintenance of BP, HR, and vasopressin release under the rest conditions at the home-cage. Furthermore, indicate that DMH is an important thermoregulatory center during exposure to RS, regulating tail artery vasoconstriction.
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Papers by Jose Antunes-Rodrigues