The aim of this study was to evaluate the morphometry and ultra structure of retinal pigmented la... more The aim of this study was to evaluate the morphometry and ultra structure of retinal pigmented layer in continuous light exposed and dark adapted domestic female cats. Twenty four healthy adult cats were divided into three groups: control, continuous light exposed and continuous dark adapted groups. The eyes of animals were routinely fixed and studied by electron microscope. The results showed that in light exposed group, the mean of thickness and number of melanosome of retinal pigmented layer had significant increment when compared with control and dark adapted groups (P<0.05). Mitochondria, golgi apparatus and rough endoplasmic reticulum were also observed to increase in the light exposed group. Our finding have confirmed that high cell activity occur in cat retinal pigmented layer under the effect of 24 h continuous light.
Journal of Pain & Palliative Care Pharmacotherapy, 2021
Abstract Dexmedetomidine (Dexdor or Precedex®) is considered as a sedative agent which is widely ... more Abstract Dexmedetomidine (Dexdor or Precedex®) is considered as a sedative agent which is widely used as an adjuvant in general anesthesia and critical care practice. There is extensive evidence indicating its neuroprotective properties especially in various ischemic and hemorrhagic brain injury models of animals. Clinical trials have shown that dexmedetomidine (DEX) can improve the outcome of intensive care unit (ICU) patients. Also, DEX is appropriate as a non-opioid analgesic therapy whenever minimizing opioid-related side effects is necessary. The present article reviews the recent advances in the use of DEX as a neuroprotective agent in both animal and human studies including newest findings about the mechanism of the drug as well as analgesic efficacy of this drug at all perioperative stages. In spite of the beneficial effects of the drug on the nervous system, there are potential adverse effects, such as hypotension and bradycardia, which can be treated pharmacologically and must be taken into consideration by clinicians.
Summary The purpose of this study was to evaluate the effects of a combination of latanoprost and... more Summary The purpose of this study was to evaluate the effects of a combination of latanoprost and pilocarpine on the intraocular pressure in experimentally glaucomatous rabbits. Ocular hypertension was induced in 11 conscious rabbits by the oral administration of tap water (70 mL/kg) via an orogastric tube. The study was conducted in three therapeutic groups to test the effects of latanoprost (group L), pilocarpine (group P) and a combination of the two drugs (group LP). After evaluating the first drug, a washout period of 1 week was allowed before the second drug was evaluated. The left eye of rabbits in group L received one drop of normal saline and one drop of 0.005% latanoprost, in group P one drop of normal saline and one drop of 2% pilocarpine and in group LP, one drop of 0.005% latanoprost and one drop of 2% pilocarpine. The right eyes of all rabbits received two drops of normal saline (as control eyes). The intraocular pressure (IOP) and pupil diameter (PD) were measured bef...
ETHNOPHARMACOLOGICAL RELEVANCE Chemotherapy-induced peripheral neuropathy (CIPN) is one of the co... more ETHNOPHARMACOLOGICAL RELEVANCE Chemotherapy-induced peripheral neuropathy (CIPN) is one of the complications vexes patients treated with anti-cancer agents. Saffron has been demonstrated to attenuate symptoms of peripheral neuropathy in animal models. Also, there is a published clinical trial that investigated the pain relieving effect of saffron following nationally accepted rules and concluded that saffron was successful in alleviating pain symptoms in patients suffering from fibromyalgia. AIM OF THE STUDY We aimed to determine the efficacy of crocin as a constituent of saffron in CIPN as the first report. MATERIALS AND METHODS One hundred and seventy-seven enrolled eligible patients (between December 2018 and March 2020) for study entry were cases demonstrating mild to severe symptomatic CIPN for at least a month. These cases were randomly assigned to two main groups including 15 mg crocin tablet, bid (30 mg total daily target dose) and placebo tablet for 8 weeks. A crossover study was performed with a 2-week washout period. Patient outcomes were measured once a week for 8 consecutive weeks. RESULTS Grade of sensory, motor and neuropathic pain decreased considerably and significantly in the crocin group compared with placebo (P < 0.05). Observed toxicities were mild and adverse effects had no significant differences between the two groups (P > 0.05). CONCLUSIONS Crocin considerably seems to be effective for relieving symptoms of CIPN in cancer patients receiving chemotherapy agents. However, further studies are needed about crocin with its beneficial neuropharmacological effects and lower adverse effects than the chemical agents such as antidepressants, lamotrigine, and gabapentin.
The lack of oral or injectable formulations of ziconotide (ω-conotoxin peptide), a novel analgesi... more The lack of oral or injectable formulations of ziconotide (ω-conotoxin peptide), a novel analgesic agent, limits research on potential neurobehavioral protective properties of this substance, including antidepressant-like effects. Here we expose rats to a stress paradigm that induces depression and memory impairment to assess the effects of ziconotide treatment. Ziconotide was administered intracerebroventricular (i.c.v.) to rats undergoing stereotaxic surgery at a single dose (1 μg/rat) or in repeated long-term applications (dosage groups: 0.1, 0.3, and 1 μg/rat). The antidepressant activity and memory-enhancing effects of ziconotide were examined via the forced swimming test, the Morris water maze test, and the passive avoidance learning test. Behavioral results showed that long-term i.c.v. ziconotide administration significantly decreased the immobility time and delayed the latency period to immobility in a dose-dependent manner compared to controls. In the passive avoidance learning test, the latency period increased, and in the Morris water maze test, the platform location latency time decreased. A single dose of ziconotide (1 μg/rat) did not show a significant effect on memory function or depression parameters during the same tests. Animals were sacrificed immediately after behavioral testing, and both hippocampi were removed and prepared for BDNF evaluation. Hippocampal BDNF levels were significantly increased in rats receiving long-term i.c.v. ziconotide compared to controls. Our results suggest that long-term consumption of ziconotide may attenuate the severity of depression-like behavior and could be useful for preventing memory impairments in various learning models by elevating BDNF levels.
OBJECTIVE Ziconotide (ω-conotoxin MVIIA peptide) is a novel analgesic agent acting on voltage-gat... more OBJECTIVE Ziconotide (ω-conotoxin MVIIA peptide) is a novel analgesic agent acting on voltage-gated calcium channels and is administered intrathecally for neuropathic pain. While antiepileptic activities of other types of calcium channel blockers (T- or L-type) are well established, there is no information regarding the effect of ziconotide as an N-type calcium channel antagonist in pentylenetetrazol-induced seizures or its anxiolytic and sedative activities. The present study is the first to report on these effects. METHODS To evaluate the anticonvulsant activity of ziconotide in the pentylenetetrazol (60 mg/kg) seizure model, ziconotide was administered intracerebroventricular (i.c.v.) as a single dose (1 μg/rat) or repeatedly (chronic administration: 0.1, 0.3, or 1 μg/rat once a day for seven days). The anxiolytic and sedative actions of ziconotide were evaluated with the elevated plus maze, light/dark (LD) box, and pentobarbital-induced sleep tests. Immediately after behavioral testing, the amygdala was completely removed bilaterally to determine corticosterone levels by immunoassay. RESULTS In all dosing regimens, ziconotide significantly decreased the seizure frequency and also delayed the latency period compared with control. Chronic administration affected the percentage of mortality protection, while a single dose of ziconotide did not. In behavioral tests, ziconotide significantly increased both the number of entries and the percentage of time spent in the open arms of the elevated plus maze. Furthermore, ziconotide significantly increased the latency period and the number of entries into the light compartment during the LD box examination. Chronic administration of ziconotide significantly reduced the latency to sleep and increased sleeping time, whereas these parameters were not affected by a single dose. Additionally, amygdala corticosterone levels were significantly decreased in rats treated with ziconotide compared with control. CONCLUSION Ziconotide displays beneficial neurobehavioral effects in a model of epilepsy with anxiety as its comorbid event. It seems that at least one of the mechanisms involved in these effects is associated with a decrease in brain corticosterone levels. The main advantage of ziconotide over benzodiazepines (routine anxiolytic and sedative drugs) is that it does not cause tolerance, dependency, and addiction. Therefore, more than ever, it is necessary to improve the convenience of drug delivery protocols and attenuate the adverse effects associated with ziconotide-based therapies.
Comparative Immunology, Microbiology and Infectious Diseases, 2019
The active ingredient of these plants is primarily alkaloids, flavonoids, pigments, phenolics, te... more The active ingredient of these plants is primarily alkaloids, flavonoids, pigments, phenolics, terpenes, starches, steroids and essential oils.Recent 2 studies have exhibited its antimicrobial effects against bacterial, fungal, parasitic and viral agents. In this study the effects against Staphylococcus aureus, Escherichia coli,
W-Conotoxin MVIIA (ziconotide or SNX-111) is an atypical analgesic drug with the water-soluble fo... more W-Conotoxin MVIIA (ziconotide or SNX-111) is an atypical analgesic drug with the water-soluble formulation and routinely is injected into the brain and spinal regions in human and animal model studies. The aim of the current study was to investigate the neurobehavioral protection of this agent as a selective N-type calcium channels antagonist following spontaneous morphine withdrawal in rats. Male rats were administered morphine (10-50 mg/kg) intraperitoneal (IP) twice daily for 7 days. Ziconotide was injected intrathecal (IT) either in chronic form (0.1, 0.3 and 1 mg/rat) concurrent with daily doses of morphine or it was injected as a single dose (1 mg/rat) on the last day. Novel object recognition task (NOR) and radial arm maze (RAM) were used in order to evaluation of the recognition and spatial working/reference memory performances, respectively. The amount of N-methyl-D-aspartate (NMDA) receptor subunits including NR2A and NR2B in the hippocampus and prefrontal cortex were determined by western blotting. We observed that abrupt cessation after chronic exposure to morphine led to decrease in both recognition and working/reference memory performances (p < .01). Spontaneous withdrawal also significantly suppressed the amount of NR2A and NR2B. This impairment was attenuated by single and chronic doses of ziconotide (p < .05). Also, expression of NR2A and NR2B were significantly increased during both drug delivery protocols. Our findings suggest that ziconotide prevents morphine withdrawal-induced memory deficits through alteration in glutamatergic transmission and regulation of NMDA receptors (NMDARs).
Abstract The effect of ω-conotoxin MVIIA (Ziconotide or SNX-111) as an inhibitor of the neuronal ... more Abstract The effect of ω-conotoxin MVIIA (Ziconotide or SNX-111) as an inhibitor of the neuronal N-type calcium channels on the signs of morphine withdrawal was investigated. The animals were rendered to physical dependence by the continuous intraperitoneal (IP) injections of gradually enhancing the doses of morphine (10–50 mg/kg) during 7 days. The withdrawal was induced in animals through the IP administration of naloxone with the dose of 2 mg/kg or it was elicited spontaneously. The single and chronic intrathecal injections of ω-conotoxin following the naloxone-precipitated withdrawal diminished the number of jumpings (p < 0.05). Moreover, both acute and chronic administrations of the drug alleviated the intensity of ptosis, piloerection, teeth chattering, diarrhea, irritability and genital grooming (p < 0.01) during the two models of the experiment. It can be concluded that the class of N-type calcium channel blockers ameliorate the severity of morphine withdrawal syndrome.
To evaluate the effect of tetracaine on intraocular pressure (IOP) in normal and hypertensive rab... more To evaluate the effect of tetracaine on intraocular pressure (IOP) in normal and hypertensive rabbit eyes. The study was conducted on 12 healthy rabbits as controls and 6 healthy rabbits in which an experimental model of ocular hypertension (OHT) was induced by administration of 70 mL/kg of tap water through an orogastric tube. One drop of tetracaine was instilled in the left eye while a drop of normal saline (placebo) was applied to the right eye of the control group. IOP was measured before and 0, 5, 10, 15, 20, 25, 30, 35 and 40 minutes after drop administration in this group. The OHT group also received one drop of tetracaine and normal saline in the left eyes and right eyes respectively, immediately after water loading; the instillation of drops was repeated after 55 minutes. IOP was measured before and 0, 5, 10, 15, 20, 25, 30, 35, 40, 55, 70, 85, 100 and 115 minutes after water loading in this group. Tetracaine treated eyes in both groups (ocular hypertensive and normal contr...
Introduction: In female rats sensitivity to antinociceptive treatment varies during different sta... more Introduction: In female rats sensitivity to antinociceptive treatment varies during different stages of the estrous cycle. The role of GABA through GABA B receptor in nociception has been established. The aim of the present study is to investigate the effect of intracerebroventicular injection of GABA B receptor agonist (baclofen) and GABA B antagonist (CGP35348) on pain sensitivity during different stages of the estrous cycle. Methods: Forty adult female rats weighing 200-220 g were used. Rats were maintained on 12 h reversed light/dark cycle, and standard temperature 22 ± 2°C. Food and water were available ad libitum. Pain sensitivity was evaluated by formalin test, performed by subcutaneous injection of 50 µl formalin solution (2.5%) into the hind paw in each stage of the estrous cycle. Data were analyzed by two-way ANOVA and Tukey test as post-hoc test. The level of significance was P<0.05. Results: Our data showed that baclofen significantly decreased pain sensitivity in all stages of estrous cycle (P<0.05). The analgesic effect of baclofen was significantly higher during metestruse and diestruse as compared to proestruse and estrus (P<0.05). CGP35348 significantly increased pain sensitivity in all stages of estrous cycle (P<0.05). The hyperalgesic effect of CGP35348 was significantly lower during metestruse and diestruse than proestruse and estrus (P<0.05). Administration of baclofen in pretreated rats with CGP35348 did not induce any significant change in pain sensitivity (P>0.05). Conclusion: We have demonstrated that GABA through GABA B receptor can modulate pain sensitivity during the estrous cycle.
Pain control during and after breast surgery is still a challenging task. Dexmedetomidine (DEX) i... more Pain control during and after breast surgery is still a challenging task. Dexmedetomidine (DEX) is considered as a sedative agent that is widely used perineurally or intravenously as an adjuvant in general anesthesia and critical care medicine practice. The aim of this study is to evaluate the efficacy of perineural DEX and intravenous (IV) DEX and their effects on postoperative complications in breast surgeries. Design: Systematic review and meta-analysis. Methods: The present study systematically reviewed all identified randomized controlled trials for efficacy and safety of IV and perineural use of DEX in breast surgeries. Databases were searched for articles published before October 2019. Findings: Twelve trials were identified including 803 patients undergoing breast surgery. Although administration of IV DEX and its use with pectoral nerve (Pecs) block significantly postponed time for first analgesic request and decreased pain score at 1 and 12 hours after surgery, paravertebral use of DEX had no statistically significant effect. Pooled data about perineural DEX showed no significant effect on postoperative nausea and vomiting (PONV), whereas IV DEX significantly reduced PONV. Pooled analysis also showed that DEX administration did not significantly affect postoperative complications, such as postoperative itching, bradycardia, and pneumothorax in patients undergoing breast surgery. Conclusions: The results showed that unlike paravertebral DEX, both DEX use with Pecs blocks and IV DEX were effective in control of postoperative pain in patients undergoing breast surgeries. Unlike perineural DEX, IV DEX significantly reduced PONV.
The aim of this study was to evaluate the morphometry and ultra structure of retinal pigmented la... more The aim of this study was to evaluate the morphometry and ultra structure of retinal pigmented layer in continuous light exposed and dark adapted domestic female cats. Twenty four healthy adult cats were divided into three groups: control, continuous light exposed and continuous dark adapted groups. The eyes of animals were routinely fixed and studied by electron microscope. The results showed that in light exposed group, the mean of thickness and number of melanosome of retinal pigmented layer had significant increment when compared with control and dark adapted groups (P<0.05). Mitochondria, golgi apparatus and rough endoplasmic reticulum were also observed to increase in the light exposed group. Our finding have confirmed that high cell activity occur in cat retinal pigmented layer under the effect of 24 h continuous light.
Journal of Pain & Palliative Care Pharmacotherapy, 2021
Abstract Dexmedetomidine (Dexdor or Precedex®) is considered as a sedative agent which is widely ... more Abstract Dexmedetomidine (Dexdor or Precedex®) is considered as a sedative agent which is widely used as an adjuvant in general anesthesia and critical care practice. There is extensive evidence indicating its neuroprotective properties especially in various ischemic and hemorrhagic brain injury models of animals. Clinical trials have shown that dexmedetomidine (DEX) can improve the outcome of intensive care unit (ICU) patients. Also, DEX is appropriate as a non-opioid analgesic therapy whenever minimizing opioid-related side effects is necessary. The present article reviews the recent advances in the use of DEX as a neuroprotective agent in both animal and human studies including newest findings about the mechanism of the drug as well as analgesic efficacy of this drug at all perioperative stages. In spite of the beneficial effects of the drug on the nervous system, there are potential adverse effects, such as hypotension and bradycardia, which can be treated pharmacologically and must be taken into consideration by clinicians.
Summary The purpose of this study was to evaluate the effects of a combination of latanoprost and... more Summary The purpose of this study was to evaluate the effects of a combination of latanoprost and pilocarpine on the intraocular pressure in experimentally glaucomatous rabbits. Ocular hypertension was induced in 11 conscious rabbits by the oral administration of tap water (70 mL/kg) via an orogastric tube. The study was conducted in three therapeutic groups to test the effects of latanoprost (group L), pilocarpine (group P) and a combination of the two drugs (group LP). After evaluating the first drug, a washout period of 1 week was allowed before the second drug was evaluated. The left eye of rabbits in group L received one drop of normal saline and one drop of 0.005% latanoprost, in group P one drop of normal saline and one drop of 2% pilocarpine and in group LP, one drop of 0.005% latanoprost and one drop of 2% pilocarpine. The right eyes of all rabbits received two drops of normal saline (as control eyes). The intraocular pressure (IOP) and pupil diameter (PD) were measured bef...
ETHNOPHARMACOLOGICAL RELEVANCE Chemotherapy-induced peripheral neuropathy (CIPN) is one of the co... more ETHNOPHARMACOLOGICAL RELEVANCE Chemotherapy-induced peripheral neuropathy (CIPN) is one of the complications vexes patients treated with anti-cancer agents. Saffron has been demonstrated to attenuate symptoms of peripheral neuropathy in animal models. Also, there is a published clinical trial that investigated the pain relieving effect of saffron following nationally accepted rules and concluded that saffron was successful in alleviating pain symptoms in patients suffering from fibromyalgia. AIM OF THE STUDY We aimed to determine the efficacy of crocin as a constituent of saffron in CIPN as the first report. MATERIALS AND METHODS One hundred and seventy-seven enrolled eligible patients (between December 2018 and March 2020) for study entry were cases demonstrating mild to severe symptomatic CIPN for at least a month. These cases were randomly assigned to two main groups including 15 mg crocin tablet, bid (30 mg total daily target dose) and placebo tablet for 8 weeks. A crossover study was performed with a 2-week washout period. Patient outcomes were measured once a week for 8 consecutive weeks. RESULTS Grade of sensory, motor and neuropathic pain decreased considerably and significantly in the crocin group compared with placebo (P < 0.05). Observed toxicities were mild and adverse effects had no significant differences between the two groups (P > 0.05). CONCLUSIONS Crocin considerably seems to be effective for relieving symptoms of CIPN in cancer patients receiving chemotherapy agents. However, further studies are needed about crocin with its beneficial neuropharmacological effects and lower adverse effects than the chemical agents such as antidepressants, lamotrigine, and gabapentin.
The lack of oral or injectable formulations of ziconotide (ω-conotoxin peptide), a novel analgesi... more The lack of oral or injectable formulations of ziconotide (ω-conotoxin peptide), a novel analgesic agent, limits research on potential neurobehavioral protective properties of this substance, including antidepressant-like effects. Here we expose rats to a stress paradigm that induces depression and memory impairment to assess the effects of ziconotide treatment. Ziconotide was administered intracerebroventricular (i.c.v.) to rats undergoing stereotaxic surgery at a single dose (1 μg/rat) or in repeated long-term applications (dosage groups: 0.1, 0.3, and 1 μg/rat). The antidepressant activity and memory-enhancing effects of ziconotide were examined via the forced swimming test, the Morris water maze test, and the passive avoidance learning test. Behavioral results showed that long-term i.c.v. ziconotide administration significantly decreased the immobility time and delayed the latency period to immobility in a dose-dependent manner compared to controls. In the passive avoidance learning test, the latency period increased, and in the Morris water maze test, the platform location latency time decreased. A single dose of ziconotide (1 μg/rat) did not show a significant effect on memory function or depression parameters during the same tests. Animals were sacrificed immediately after behavioral testing, and both hippocampi were removed and prepared for BDNF evaluation. Hippocampal BDNF levels were significantly increased in rats receiving long-term i.c.v. ziconotide compared to controls. Our results suggest that long-term consumption of ziconotide may attenuate the severity of depression-like behavior and could be useful for preventing memory impairments in various learning models by elevating BDNF levels.
OBJECTIVE Ziconotide (ω-conotoxin MVIIA peptide) is a novel analgesic agent acting on voltage-gat... more OBJECTIVE Ziconotide (ω-conotoxin MVIIA peptide) is a novel analgesic agent acting on voltage-gated calcium channels and is administered intrathecally for neuropathic pain. While antiepileptic activities of other types of calcium channel blockers (T- or L-type) are well established, there is no information regarding the effect of ziconotide as an N-type calcium channel antagonist in pentylenetetrazol-induced seizures or its anxiolytic and sedative activities. The present study is the first to report on these effects. METHODS To evaluate the anticonvulsant activity of ziconotide in the pentylenetetrazol (60 mg/kg) seizure model, ziconotide was administered intracerebroventricular (i.c.v.) as a single dose (1 μg/rat) or repeatedly (chronic administration: 0.1, 0.3, or 1 μg/rat once a day for seven days). The anxiolytic and sedative actions of ziconotide were evaluated with the elevated plus maze, light/dark (LD) box, and pentobarbital-induced sleep tests. Immediately after behavioral testing, the amygdala was completely removed bilaterally to determine corticosterone levels by immunoassay. RESULTS In all dosing regimens, ziconotide significantly decreased the seizure frequency and also delayed the latency period compared with control. Chronic administration affected the percentage of mortality protection, while a single dose of ziconotide did not. In behavioral tests, ziconotide significantly increased both the number of entries and the percentage of time spent in the open arms of the elevated plus maze. Furthermore, ziconotide significantly increased the latency period and the number of entries into the light compartment during the LD box examination. Chronic administration of ziconotide significantly reduced the latency to sleep and increased sleeping time, whereas these parameters were not affected by a single dose. Additionally, amygdala corticosterone levels were significantly decreased in rats treated with ziconotide compared with control. CONCLUSION Ziconotide displays beneficial neurobehavioral effects in a model of epilepsy with anxiety as its comorbid event. It seems that at least one of the mechanisms involved in these effects is associated with a decrease in brain corticosterone levels. The main advantage of ziconotide over benzodiazepines (routine anxiolytic and sedative drugs) is that it does not cause tolerance, dependency, and addiction. Therefore, more than ever, it is necessary to improve the convenience of drug delivery protocols and attenuate the adverse effects associated with ziconotide-based therapies.
Comparative Immunology, Microbiology and Infectious Diseases, 2019
The active ingredient of these plants is primarily alkaloids, flavonoids, pigments, phenolics, te... more The active ingredient of these plants is primarily alkaloids, flavonoids, pigments, phenolics, terpenes, starches, steroids and essential oils.Recent 2 studies have exhibited its antimicrobial effects against bacterial, fungal, parasitic and viral agents. In this study the effects against Staphylococcus aureus, Escherichia coli,
W-Conotoxin MVIIA (ziconotide or SNX-111) is an atypical analgesic drug with the water-soluble fo... more W-Conotoxin MVIIA (ziconotide or SNX-111) is an atypical analgesic drug with the water-soluble formulation and routinely is injected into the brain and spinal regions in human and animal model studies. The aim of the current study was to investigate the neurobehavioral protection of this agent as a selective N-type calcium channels antagonist following spontaneous morphine withdrawal in rats. Male rats were administered morphine (10-50 mg/kg) intraperitoneal (IP) twice daily for 7 days. Ziconotide was injected intrathecal (IT) either in chronic form (0.1, 0.3 and 1 mg/rat) concurrent with daily doses of morphine or it was injected as a single dose (1 mg/rat) on the last day. Novel object recognition task (NOR) and radial arm maze (RAM) were used in order to evaluation of the recognition and spatial working/reference memory performances, respectively. The amount of N-methyl-D-aspartate (NMDA) receptor subunits including NR2A and NR2B in the hippocampus and prefrontal cortex were determined by western blotting. We observed that abrupt cessation after chronic exposure to morphine led to decrease in both recognition and working/reference memory performances (p < .01). Spontaneous withdrawal also significantly suppressed the amount of NR2A and NR2B. This impairment was attenuated by single and chronic doses of ziconotide (p < .05). Also, expression of NR2A and NR2B were significantly increased during both drug delivery protocols. Our findings suggest that ziconotide prevents morphine withdrawal-induced memory deficits through alteration in glutamatergic transmission and regulation of NMDA receptors (NMDARs).
Abstract The effect of ω-conotoxin MVIIA (Ziconotide or SNX-111) as an inhibitor of the neuronal ... more Abstract The effect of ω-conotoxin MVIIA (Ziconotide or SNX-111) as an inhibitor of the neuronal N-type calcium channels on the signs of morphine withdrawal was investigated. The animals were rendered to physical dependence by the continuous intraperitoneal (IP) injections of gradually enhancing the doses of morphine (10–50 mg/kg) during 7 days. The withdrawal was induced in animals through the IP administration of naloxone with the dose of 2 mg/kg or it was elicited spontaneously. The single and chronic intrathecal injections of ω-conotoxin following the naloxone-precipitated withdrawal diminished the number of jumpings (p < 0.05). Moreover, both acute and chronic administrations of the drug alleviated the intensity of ptosis, piloerection, teeth chattering, diarrhea, irritability and genital grooming (p < 0.01) during the two models of the experiment. It can be concluded that the class of N-type calcium channel blockers ameliorate the severity of morphine withdrawal syndrome.
To evaluate the effect of tetracaine on intraocular pressure (IOP) in normal and hypertensive rab... more To evaluate the effect of tetracaine on intraocular pressure (IOP) in normal and hypertensive rabbit eyes. The study was conducted on 12 healthy rabbits as controls and 6 healthy rabbits in which an experimental model of ocular hypertension (OHT) was induced by administration of 70 mL/kg of tap water through an orogastric tube. One drop of tetracaine was instilled in the left eye while a drop of normal saline (placebo) was applied to the right eye of the control group. IOP was measured before and 0, 5, 10, 15, 20, 25, 30, 35 and 40 minutes after drop administration in this group. The OHT group also received one drop of tetracaine and normal saline in the left eyes and right eyes respectively, immediately after water loading; the instillation of drops was repeated after 55 minutes. IOP was measured before and 0, 5, 10, 15, 20, 25, 30, 35, 40, 55, 70, 85, 100 and 115 minutes after water loading in this group. Tetracaine treated eyes in both groups (ocular hypertensive and normal contr...
Introduction: In female rats sensitivity to antinociceptive treatment varies during different sta... more Introduction: In female rats sensitivity to antinociceptive treatment varies during different stages of the estrous cycle. The role of GABA through GABA B receptor in nociception has been established. The aim of the present study is to investigate the effect of intracerebroventicular injection of GABA B receptor agonist (baclofen) and GABA B antagonist (CGP35348) on pain sensitivity during different stages of the estrous cycle. Methods: Forty adult female rats weighing 200-220 g were used. Rats were maintained on 12 h reversed light/dark cycle, and standard temperature 22 ± 2°C. Food and water were available ad libitum. Pain sensitivity was evaluated by formalin test, performed by subcutaneous injection of 50 µl formalin solution (2.5%) into the hind paw in each stage of the estrous cycle. Data were analyzed by two-way ANOVA and Tukey test as post-hoc test. The level of significance was P<0.05. Results: Our data showed that baclofen significantly decreased pain sensitivity in all stages of estrous cycle (P<0.05). The analgesic effect of baclofen was significantly higher during metestruse and diestruse as compared to proestruse and estrus (P<0.05). CGP35348 significantly increased pain sensitivity in all stages of estrous cycle (P<0.05). The hyperalgesic effect of CGP35348 was significantly lower during metestruse and diestruse than proestruse and estrus (P<0.05). Administration of baclofen in pretreated rats with CGP35348 did not induce any significant change in pain sensitivity (P>0.05). Conclusion: We have demonstrated that GABA through GABA B receptor can modulate pain sensitivity during the estrous cycle.
Pain control during and after breast surgery is still a challenging task. Dexmedetomidine (DEX) i... more Pain control during and after breast surgery is still a challenging task. Dexmedetomidine (DEX) is considered as a sedative agent that is widely used perineurally or intravenously as an adjuvant in general anesthesia and critical care medicine practice. The aim of this study is to evaluate the efficacy of perineural DEX and intravenous (IV) DEX and their effects on postoperative complications in breast surgeries. Design: Systematic review and meta-analysis. Methods: The present study systematically reviewed all identified randomized controlled trials for efficacy and safety of IV and perineural use of DEX in breast surgeries. Databases were searched for articles published before October 2019. Findings: Twelve trials were identified including 803 patients undergoing breast surgery. Although administration of IV DEX and its use with pectoral nerve (Pecs) block significantly postponed time for first analgesic request and decreased pain score at 1 and 12 hours after surgery, paravertebral use of DEX had no statistically significant effect. Pooled data about perineural DEX showed no significant effect on postoperative nausea and vomiting (PONV), whereas IV DEX significantly reduced PONV. Pooled analysis also showed that DEX administration did not significantly affect postoperative complications, such as postoperative itching, bradycardia, and pneumothorax in patients undergoing breast surgery. Conclusions: The results showed that unlike paravertebral DEX, both DEX use with Pecs blocks and IV DEX were effective in control of postoperative pain in patients undergoing breast surgeries. Unlike perineural DEX, IV DEX significantly reduced PONV.
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