فهرست مطالب

Physiology and Pharmacology
Volume:22 Issue: 2, Jun 2018

  • تاریخ انتشار: 1397/03/02
  • تعداد عناوین: 8
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  • Sahand Asharfpour, Fereshteh Pourabdolhossein, Forough Ebrahim Tabar, Manouchehr Ashrafpour, Mojdeh Navidhamidi, Sima Shahabi, Maryam Ghasemi-Kasman, Alireza Asgari Pages 73-81
    Introduction
    Synaptosomes are sealed particles that contain mitochondria, cytoskeleton and vesicles which are necessary to synaptic events like neurotransmitter release and uptake in the nervous system. However, the effect of high and low temperatures on synaptosome membrane integrity and function during a time course after its extraction is less known. The purpose of this study was to assess synaptosome viability and function at 37, 4°C and room temperature (RT) during 6 hours after its extraction.
    Methods
    Hippocampi of 40 male Wistar rats were used for synaptosome preparation. To ensure synaptosome membrane integrity and function, lactate dehydrogenase activity (LDH) and GABA uptake were assessed during 6 successive hours after their extraction at 37, 4°C and RT.
    Results
    Our results showed that at 37°C, synaptosome membrane integrity was reduced 3 hours but at 4°C and RT, it occurred 5 hours following their extraction. The results of synaptosome function analysis coincide with LDH enzyme assay data, meaning that GABA uptake faced a 50% reduction from the initial value at 37°C after 3 hours and at RT after 5 hours. We also found that GABA uptake was reduced at 4°C in the first hour after extraction because the low temperature inhibits GABA transporters.
    Conclusion
    Synaptosomes preserved their viability and function at RT, 37 and 4°C at least for 3 hours after extraction and reduced over time. For long term application of synaptosomes, it is better to keep them at 4°C.
    Keywords: Synaptosome, Viability, LDH activity, GABA uptake, Hippocampus
  • Mina Sadat Izadi, Maryam Radahmadi, Maedeh Ghasemi, Atefeh Rayatpour Pages 82-91
    Introduction
    Psychological stresses influence brain functions such as learning and memory. Environmental factors like types and durations of stress affect brain responsiveness. This study investigated the effects of two subchronic social and isolation stresses on learning, memory, adrenal glands weight and corticosterone levels in the hippocampus and frontal cortex.
    Methods
    Eighteen male rats were randomly allocated into three experimental groups: control, social stress and isolation stress groups. Rats were under stresses for 7 days. Latency of entrance into the dark room was evaluated as brain function, using the passive avoidance test before inducing of electrical shock (as initial latency) and on days 1, 3, 5 and 7 after foot shock. In addition, corticosterone levels were measured in the homogenized hippocampus and frontal cortex.
    Results
    The latencies of days 1, 3 and 5 were significantly lower in an isolation stress group than the control group. The latency of day 7 significantly decreased in social and isolation stress groups, compared to the control group. The adrenal glands weight showed significant enhancements in social and isolation stress groups, compared to the control group. Although, the weight of the adrenal glands significantly increased in an isolation stress group, compared to the social stress group. There was a significant enhancement in the corticosterone levels in the hippocampus, but not frontal cortex in isolation stress group.
    Conclusion
    It was concluded that subchronic isolation stress severely deteriorated brain functions (learning and memory) compared to the subchronic social stress. In addition, isolation stress affected corticosterone levels in the hippocampus more than frontal cortex.
    Keywords: Learning, memory, Social stress, Isolation stress, Adrenal glands, Corticosterone
  • Reza Naeimi, Maryam Ghasemi-Kasman, Sohrab Kazemi, Manouchehr Ashrafpour, Ali Akbar Moghadamnia, Fereshteh Pourabdolhossein Pages 92-102
    Introduction
    Recently, herbal medicine is widely used as an alternative and complementary therapy in several neurological disorders such as epilepsy. The anti-inflammatory and neuroprotective effects of Zingiber officinale or ginger have been well-documented. The present study was designed to evaluate the effects of ginger extract pre-treatment on seizures behavior, neuronal density and astrocytes activation in pentylenetetrazol (PTZ)- induced kindling model.
    Methods
    Kindling model was induced in mice by repetitive administration of PTZ at sub convulsive dose. Hydroalcoholic extract of ginger at doses of 25, 50 or 100 mg/kg were daily injected 10 days before PTZ injections and intraperitoneal administration of extract was continued 1h before each PTZ injection. Immunostaining against NeuN and GFAP as neuronal and astrocyte markers, respectively, was carried out on brain tissue sections.
    Results
    Our data showed that ginger extract pre-treatment, especially at dose of 100 mg/kg, reduced the seizures behavior in PTZ receiving animals. Immunostaining against NeuN biomarker demonstrated that neuronal death was alleviated in animals under treatment of ginger extract. Furthermore, application of ginger extract attenuated the number of GFAP expressing cells in hippocampus of fully-kindled animals.
    Conclusion
    Overall, our data suggest that ginger pre-treatment exerts significant neuroprotective effect by attenuation of astrocytes activation in PTZ-induced kindling model. It can be concluded that ginger might be used as effective supplementary agent in epileptic patients.
    Keywords: Kindling, Pentylenetetrazol, Zingiber officinale, Neuroprotection, Astrocytes activation
  • Batool Kamali Manesh, Ehsan Mohebi, Hassan Azhdari Zarmehri, Ali Shamsizadeh, Mohammad Mohammad-Zadeh Pages 103-108
    Introduction
    Epilepsy is one of the most common and chronic neurological disorders. It appears periodically and usually is concomitant with unpredictable seizures due to abnormal discharge of brain neurons. In this study, we investigated the anticonvulsant effect of ascorbic acid (AA) on seizures induced by pentylenetetrazole (PTZ) in male rats.
    Methods
    In this study PTZ (37 mg/kg) was injected every other day to induce kindling in male rats. AA (12.5, 25 and 50 mg/kg) was administered into the right lateral ventricle 30 minute before every PTZ injection. The seizure parameters were measured during 30 min after PTZ injection.
    Results
    Administration of 12.5 mg/kg of AA increased stage 4 latency compared to vehicle group. Conversely, 50 mg/kg of AA decreased stage 1 and 2 latency, increased stage 5 duration and decreased number of PTZ injections needed to achieve stage 5 seizure compared to vehicle treated animals.
    Conclusion
    It seems that the AA has dual effects on seizure parameters induced by PTZ. Low doses (12.5 mg/kg) have protective effects while high doses (50 mg/kg) have proconvulsant effects on seizure.
    Keywords: Ascorbic acid, Epilepsy, Pentylenetetrazole, Rat
  • Maryam Moghimian, Somaye Aalami, Seyed-Hosein Abtahi-Evari, Malihe Soltani Pages 109-117
    Introduction
    To study the effect of withdrawal syndrome in morphine-dependent male rats.
    Methods
    Adult male rats were divided randomly into four groups: control (G1), received morphine (G2), received morphine and treated by clove (G3) and only treated by clove (G4). The rats were administered increasing doses of morphine (0.1, 0.2 and 0.3 mg/ml), each dose being administered for two days, and then a dose of 4 mg/ml was given every day for 21 consecutive days. After the last oral dose of morphine on day 21, the rats were treated daily with oral clove (4 mg/ml/kg) for 14 days. Following the treatment, the histological parameters, oxidative stress, LH, FSH and testosterone levels were measured.
    Results
    The histological parameters were not significantly changed. In the morphine group, it was observed that the levels of LH, FSH and testosterone decreased significantly in comparison to the control group and clove treatment could significantly increase the LH, FSH, testosterone, glutathione peroxidase and superoxide dismutase levels in G3 groups. Also, the level of malondialdehyde (MDA) increased significantly in the morphine group and treatment with clove could significantly decrease the MDA level in G3 groups.
    Conclusion
    Our results showed that the hormone levels (LH, FSH and testosterone) and antioxidant enzyme increased with the administration of clove after morphine withdrawal. This may be because of the antioxidant effect of clove or the direct effect of this plant on the hypothalamic–pituitary–gonadal axis, or both.
    Keywords: Syzygium aromaticum, Morphine withdrawal, Testosterone, Antioxidant, Reproductive system
  • Mahnaz Taherianfard, Mehdi Karamifard Pages 118-123
    Introduction
    : It seems that Valeriana officinalis (valerian) extract through gamma-amino-butyric acid A (GABAA) receptor possesses analgesic effect. The aim of the present study was to investigate the effect of muscimol and picrotoxin on pain sensitivity in male rats pretreated with valerian extract using the formalin test.
    Methods
    Thirty-five male rats weighing 200-250g in standard temperature 20±2 °C and light cycle of 12/12h used. Animals were randomly divided to 7 groups: sham 1 (injection of saline); sham 2 (pretreated with valerian ICV injection of artificial cerebro spinal fluid); experimental1 (injection of valerian extract); experimental 2 or 3 (pretreated with valerian extract ICV injection of muscimol 250 and 500 ng/rat); experimental 4 or 5 (pretreated with valerian extract ICV injection of picrotoxin 250 and 500 ng/rat). Valerian extract 400 mg/kg was administrated by intraperitoneal injection. Pain evaluation was done by the formalin test. Lateral ventricles cannulated unilaterally by the stereotaxic procedure.
    Results
    Data showed that valerian extract significantly decreased pain sensitivity in the late phase of the formalin test in comparison to sham 1 group. Muscimol in both doses significantly decreased pain in comparison to sham 1, while at the dose of 500 ng/rat significantly increased pain sensitivity in comparison to sham 2 at late phases of formalin test. Picrotoxin at both doses significantly decreased pain sensitivity in comparison to sham 1, while significantly increased pain sensitivity in comparison to the sham 2 at late phases of formalin test.
    Conclusion
    According to present results, valerian extract had analgesic effect through the GABAA receptor.
    Keywords: Valeriana officinalie, Musciol, Picrotoxin, Pain, Rat
  • Maedeh Ghasemi, Nasrin Mehranfard, Hojjatallah Alaei Pages 124-132
    Introduction
    A specific role of dopamine D2 receptor signaling of midbrain and hypothalamic dopaminergic systems has not been yet identified in energy homeostasis. Here, we investigated effects of intra-ventromedial hypothalamus (VMH) administration of the D2 receptor agonist (quinpirole) and antagonist (sulpiride) on plasma leptin and glucose levels in fasted rats.
    Methods
    A guide cannula was stereotaxically implanted in the VMH of male Wistar rats (n=6/group). In experiment day, the fasted rats (20-24h) received a recommended dose of D2 receptor agonist (quinpilroe: 0.5μg), antagonist (sulpiride: 0.005μg) and saline (0.5μl) injected into the VMH. Blood samples were collected at 0, 30 and 60 min after injection, and plasma leptin and glucose were measured by Eliza kit and glucose oxidase method, respectively.
    Results
    Plasma leptin significantly increased in a time dependent manner in quinpirole group compared to control (P
    Conclusion
    These data suggest that altered the VMH D2-mediated neurotransmission might contribute to an alteration in the metabolic phenotype (leptin secretion and plasma glucose level) of rats.
    Keywords: Dopamine, D2 receptor, Glucose, leptin, Ventromedial nucleus
  • Alireza Samimiat, Mohammad Sedigh Khosravi, Jalal Hassanshahi, Mehdi Nematbakhsh Pages 133-140
    Introduction
    Renal ischemia-reperfusion (RIR) may disturb renin-angiotensin system components. In this study, the effects of Mas receptor (A779) and AT2 receptor (PD123319) antagonists were examined in RIR rats.
    Methods
    Total 60 male and female Wistar rats were assigned into 10 groups (n=6 in each group), including sham-operated group, RIR groups treated with the vehicle, A779, PD123319, or A779㰽盟絽. The rats were subjected to 30 minutes renal ischemia followed by 75 minutes reperfusion and the vehicle/antagonists were started to infuse 15 minutes after beginning of reperfusion for 60 min. Mean arterial pressure (MAP) and renal perfusion pressure responses to antagonists were assessed. Measurements for kidney function parameters also were performed. All the measurements were made at the end of 60 min vehicle/antagonist infusion.
    Results
    MAP has altered significantly during RIR times (P=0.004), but no significant difference was observed between two genders. The RIR itself in injured rats (compared to sham operated rats) decreased urine flow (UF), creatinine clearance (Ccr), filtrate load of sodium (FNa) and sodium excretion rate (ENa) significantly in both genders (P
    Conclusion
    Our findings showed the importance role of Mas receptor and AT2 receptor on renal function after kidney ischemia/reperfusion in RIR rat model.
    Keywords: Renal ischemia-reperfusion, Mas receptor, AT2 receptor, Renal Function, Gender