Veterinary Research Forum

Abstract Thymoquinone (TQ), the bioactive compound found in black seed, possesses beneficial properties. In the present study, the effects of oral administration of TQ were investigated on acute corneal and orofacial pains in rats. To clarify the central mechanism of action, muscarinic cholinergic, cannabinergic 1 (CB1) and 5-hydroxytryptamine receptor antagonists were delivered into the 4^th ventricle of the brain after oral administration of TQ. Acute corneal and orofacial pains were induced by dropping of hypertonic saline (50.00 µL; 5.00 M) on the corneal surface and subcutaneous injection of capsaicin (1.50 µg; 20.00 µL) in the vibrissal pad, respectively. The eye wiping number and face rubbing duration were recorded as corneal and orofacial pains behavioral responses, respectively. Locomotor activity was measured using an open-field test. The TQ (5.00 mg kg^-1) had no effects, while it reduced pain responses at 10.00, 20.00, and 40.00 mg kg^-1. Intracerebro-ventricular injections of naloxone (an antagonist of opioid receptors), (N-(Piperidin-1-yl)-5-(4-iodophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide (an antagonist of CB1 receptors), atropine (an antagonist of muscarinic cholinergic receptors), and ondansetron (an antagonist of 5-hydroxytryptamine 3 receptors) at a similar dose of 10.00 µg kg^-1 inhibited corneal and orofacial pains suppression caused by 40.00 mg kg^-1 TQ. The tested drugs did not affect locomotor activity. It is concluded that TQ caused analgesia in the acute corneal and orofacial pains. Central opioid, cholinergic muscarinic, CB1, and 5-hydroxytryptamine 3 receptors might be involved in the anti-nociceptive effects of TQ.

Abstract Obese and overeating children are at risk of obesity and its complications in adulthood. Research on childhood obesity encounters numerous challenges in mammals. Broiler chicks are a suitable animal model for studying childhood obesity. Genetically, broiler chicks exhibit high growth rates. They are hyperphagic, hyperglycemic, and capable of accumulating abdominal fat, and their diet can be managed from birth. Soybean oil, which is rich in omega-6 (n-6) polyunsaturated fatty acid linoleic acid and low in omega-3 (n-3) polyunsaturated fatty acid (n-6 : n-3 ratio = 7.50), is widely utilized in human nutrition. However, conflicting findings have been reported regarding the efficacy of this oil in humans and rodents. Effects of a soybean oil-enriched diet (4.00% total fat as a control vs. 11.00% total fat as a treatment) on metabolic disorders in broiler chicks were evaluated from hatching to 36 days of age. Results showed no changes in food intake, body weight, appetite-regulating neuro-peptide mRNA levels, blood triglycerides, or hematological parameters. In contrast, the relative abdominal fat, blood cholesterol, aortic wall thickness, intima layer, and area of fat cells increased significantly in treatment group compared to control group. Signs of liver fat infiltration (steatosis) and changes in the aortic intima layer, including increased distance between elastin fibers, were observed. In conclusion, in middle-term-fed broiler chicks, a model for childhood obesity using soybean oil high in omega-6 polyunsaturated fatty acids leads to early atherosclerosis, fatty liver, adipose dysfunction, and hypercholesterolemia, without impacting body weight or food intake.

Abstract Polycystic ovary syndrome (PCOS) is a complex endocrine disorder. Exercise is one of the interventions that leads to PCOS improvement. This study aimed to investigate the potential of different durations of high-intensity interval training (HIIT) or continuous training (CT) with/ without metformin (MET) in a rat model of PCOS. For this purpose, the rats were randomly placed in seven groups, including control, PCOS, PCOS + CT, PCOS + HIIT, PCOS + MET, PCOS + MET + CT, and PCOS + MET + HIIT. The PCOS was induced by a single intra-muscular injection of 2.00 mg kg-1 estradiol valerate. The concentration of lipid indices showed that serum cholesterol and low-density lipoprotein decreased, and high-density lipoprotein increased with 8 and 12 weeks of exercise training in PCOS + CT, PCOS + HIIT, PCOS + MET + CT, and PCOS + MET + HIIT groups compared to the PCOS group, but no significant difference was found between groups. Triglyceride level decreased in treated groups with 12 weeks of exercise compared to the PCOS group, and there was no significant difference between the treated groups. Finally, serum malondialdehyde level decreased in groups received exercise intervention alone or combined with MET compared to the PCOS group. These findings revealed that HIIT and CT with longer periods with/without MET can lead to improvement of lipid profile and malondialdehyde level of PCOS patients.

Abstract Adding trace minerals to animal diets has a positive impact on reproductive performance. This study aimed to investigate whether supplementing zinc, manganese, and copper affects the testosterone level, sperm quality, and anti-oxidant enzyme activities in rams. Ten mature Afshari rams (2.50 years old; weighing 100 ± 3.29 kg) were fed a nutritionally adequate diet for 11 weeks, half of which receiving a sulfated zinc, manganese, and copper in their daily concentrates (supplemented group), while the other half served as a control group receiving no mineral in the concentrates. Ejaculate volume, as well as sperm concentration, motility, viability, morphology, and membrane integrity were assessed. From week five onwards, all parameters were significantly higher in the supplemented group. Additionally, the percentage of abnormal sperm was lower, anti-oxidant enzymes activities in the seminal plasma were improved, and plasma testosterone concentration was higher in the supplemented group compared to the control group. However, alkaline phosphatase activity was not significantly different. Furthermore, seminal plasma concentrations of copper, zinc, and manganese at the end of the study were higher in the supplemented group compared to pre-treatment levels, while these parameters were decreased in the control group. Overall, co-supplementing copper, zinc, and manganese in rams maintained the sperm quantity and quality, as well as seminal plasma anti-oxidant capacity, emphasizing the importance of studied elements in ram reproduction.

Abstract Surgery commonly causes post-operative pain that should be alleviated to prevent complications. In addition to the use of synthetic drugs, there has been a widespread desire to use medicinal plants for surgical pain management. Thymoquinone (TQ), a constituent of Nigella sativa black seeds, exhibits a potent anti-oxidant property. Celecoxib (CLX), a potent non-steroidal anti-inflammatory drug, is widely used in pain management. In the present study, the effects of TQ and CLX on pain caused by hind paw surgical incision were compared. Fifty-six rats were divided into four groups of 14 rats as intact, vehicle, TQ, and CLX groups. In each group, six rats were planned to record pain-related behaviors on days 1 - 10 and eight rats were designed for determination of serum biochemical alterations on days 1 (four rats) and 3 (four rats) after surgery. Oral administrations of TQ and CLX at a same dose of 10.00 mg kg^-1 alleviated paw lifting number (spontaneous pain) and paw withdrawal threshold evoked by von Frey filaments on metal mesh floor, improved the decreased contents of serum total anti-oxidant capacity and superoxide dismutase, and restored the increased levels of serum malondialdehyde and tumor necrosis factor-alpha. The results suggested that TQ by employing anti-oxidant and anti-inflammatory mechanisms, might relieve the pain induced by hind paw plantar incision, being comparable with CLX.

Abstract Cardiac mitochondrial dysfunction is an important feature of aged heart. However, there is still no potent agent to ameliorate cardiac function abnormalities in aged hosts. Olive oil (OLO), containing monounsaturated fatty acids, has diverse protective effects on the cardiovascular system, including anti-diabetic, anti-inflammatory, and anti-hypertensive effects. We evaluated the beneficial impacts of OLO against aging-related cardiac dysfunction. Wistar rats were randomly allotted into three groups with eight rats, including control, aged rats receiving D-galactose (D-GAL), and aged rats administrated with D-galactose plus OLO (D-GAL + OLO). Aged animals were received D-GAL at a dose of 150.00 mg kg^-1 daily through intra-peritoneal injection for aging induction. The animals in D-GAL + OLO group were co-administrated with oral OLO at a dose of 1.00 mL kg^-1 by gavage feeding daily. The administration term was eight weeks. A histological examination of heart tissue was performed. The heart tissues were also harvested to assay the oxidative stress and molecular parameters. The aged animals showed cardiac hypertrophy, increased malondialdehyde level and Bax expression, and reduced mitofusin 2, phosphatase and tensin homologue-induced putative kinase 1, dynamin-related protein 1, and Bcl2 expressions in comparison with the control animals. The OLO treatment ameliorated all these parameters. Overall, OLO could improve cardiac aging through reducing oxidative stress, enhancing genes mediated mitophagy, and improving genes mediated apoptosis in the heart.

Abstract Investigating the mechanisms responsible for pain processing of natural and synthetic chemical compounds is necessary to optimize pain management. Curcumin (Cur), the active ingredient of turmeric, exhibits potent analgesic and anti-inflammatory properties by employing multiple mechanisms at the local peripheral, spinal and supra-spinal levels. This study was aimed to investigate the effect of oral administration of Cur on muscle pain induced by intramuscular (IM) injection of formalin. To explore the possible local mechanisms, a cyclooxygenase (COX) inhibitor, diclofenac (Dic) and a COX product, prostaglandin E₂ (PGE₂), were applied. The IM injection of formalin (25.00 µL, 2.50%) into the gastrocnemius muscle induced two distinct phases of hind leg flinching. A short-lasting (10 min) hind leg lifting was observed following IM injection of PGE₂ (2 µg kg^-1, 25.00 µL). Oral administration of Cur (25.00 and 100 mg kg^-1) and IM injection of 40.00 µg kg^-1 Dic attenuated formalin and PGE2 induced nociceptive behaviors. Contra-lateral IM injection of Dic did not change muscle pain induced by ipsilateral IM injection of formalin and PGE₂. The second phase of formalin induced flinching as well as PGE₂ evoked lifting were more suppressed when 40.00 µg kg^-1 Dic and 100 mg kg^-1 Cur were used together. Locomotor activity was not changed by the above-mentioned treatments. It was concluded that the reducing effect of muscle pain of Cur might be related to the local inhibition of COX.

Abstract Thymoquinone (TQ) is the main biologically active substance of Nigella sativa (black seeds). It has anti-cancer, anti-inflammatory, anti-diabetic, anti-oxidative and anti-nociceptive properties. This study was aimed to explore the effect of TQ on acetic acid-induced visceral nociception. The central mechanisms of the effect of TQ were investigated using cannabinergic (AM251) and α₂-adrenergic (yohimbine [Yoh]) antagonists. The lateral ventricle of the brain was cannulated for intracerebroventricular (ICV) injections. Visceral nociception was induced by intra-peritoneal (IP) injection of acetic acid (1.00% in a volume of 1.00 mL). Measuring the latency time to the first writhing appearance and counting the number of writhing in 5-min intervals for a period of 60 min were performed. Locomotor activity was determined using an open-field test. Oral administration (PO) of 2.50 and 10.00 mg kg^-1 TQ increased the latency time to the first writhing appearance and decreased the number of writhing. The AM251 (5.00 µg per rat; ICV) and Yoh (5.00 µg per rat; ICV) partially prevented TQ (10.00 mg kg^-1; PO)-induced anti-nociception. Locomotor activity was not altered by these treatments. The results of the present study showed that TQ had the ability to reduce visceral nociception caused by IP injection of acetic acid. The central mechanisms of this action of TQ might be partially mediated by cannabinergic and α₂-adrenegic receptors.

Abstract Studies conducted on animal models have shown that the administration of glycerol can lead to kidney tissue damage and impaired renal function. This is believed to be caused by oxidative stress and inflammation, which in turn can result in elevated levels of blood urea nitrogen (BUN) and creatinine. These metabolites are commonly used as indicators of renal function. The aim of the current experimental research was to investigate the protective efficacy of ellagic acid in a rat model of rhabdomyolysis induced by glycerol. Sixty healthy adult male Wistar rats weighing between 250 - 300 g were divided into five equal groups including control, rhabdomyolysis (administered 8.00 mL kg^-1 of glycerol), and three rhabdomyolysis plus various doses of ellagic acid (25.00, 50.00 and 100 mg kg^-1 per day; 72 hr after receiving glycerol for 14 days successively) groups. Serum levels of BUN, creatinine, lactate dehydrogenase, alkaline phosphatase, electrolytes and inflammatory cytokines were evaluated in all rats. Histopathological studies were also performed on kidney tissues from all groups. The administration of ellagic acid resulted in a significant increase in renal function biomarkers compared to the rats with acute kidney injury. This increase was consistent with notable reductions in tumor necrosis factor-α levels and increases in interleukin-10 levels observed in blood samples. Furthermore, the improvement in histopathological indices observed in rats received ellagic acid confirmed its nephroprotective role. The results of the current experimental study suggest that ellagic acid can improve kidney damage following glycerol injection, potentially by modulating the inflammatory process.

Abstract Neuroprotective effects for natural products are supported by several studies. In this regard, safranal, a constitute of saffron, has the potential to exert beneficial effects in neurological disorders such as Parkinson's disease, epilepsy, stroke, multiple sclerosis and Alzheimer's disease. Here, we investigated the effect of safranal on penicillin-induced epileptiform activity. Also, the effects of intracerebroventricular (ICV) microinjection of AM251 as a CB1-cannabinoid receptors antagonist to clarify the possible mechanism of safranal were evaluated. Epileptiform activity was induced by intra-cortical administration of penicillin (300 IU, 1.50 μL) in urethane-anesthetized rats. Electrocorticographic recordings were used to analyze the frequency and amplitude of spike waves. Intraperitoneal injections of safranal at doses of 1.00 and 4.00 mg kg^-1 significantly reduced both the number and amplitude of spike waves. The ICV microinjection of AM251 (0.50 μg 2.00 μL^-1) significantly increased the frequency and amplitude of spike waves. In addition, the anti-epileptic effect induced by administration of safranal at a dose of 4.00 mg kg^-1 was partially prevented by ICV microinjection of 0.50 μg 2.00 μL^-1 of AM251. The results showed anti-epileptiform activities for safranal. Central CB1 cannabinergic receptors might be involved in the anti-epileptiform activity of safranal.

Abstract Activity patterns and time budgets play a crucial role in the successful farming and management of animals. In this study, the behavior patterns of 53 forest musk deer (Moschus berezovskii) were analyzed from October 2^nd to 16^th, 2021, throughout the day and night. The results showed a distinct dawn–dusk activity rhythm in the captive forest musk deer with a peak activity observed at dawn (07:00 - 10:00) and dusk (16:00 - 19:00). Additionally, there were smaller activity peaks lasting less than an hour during the nighttime (00:00 - 04:00). Comparing behavior ratios between peak and off-peak periods, it was evident that all behaviors, except rumination (RU), showed significant differences. Furthermore, no significant differences were found in the behavior ratios of the forest musk deer between the daytime and night-time. During the daytime, the percentages of time spent performing locomotion (32.87 ± 3.38%), feeding (14.43 ± 1.81%), and RU (5.62 ± 1.46%) were slightly higher compared to the night-time. Based on these findings, it is important to match the management strategies for musk deer farming with the animals' activity patterns and behavioral rhythms. Doing so can enhance farming outputs and contribute to the welfare of captive forest musk deer.

Abstract The cerebellum and its deep nuclei contribute to the regulation of important functions including motor coordination and pain. Histamine modulates some functions of the fastigial nucleus (FN) such as motor coordination. In this study, by application of histamine and activation of its H₁ and H₂ receptors, the FN processing of visceral pain, general locomotor activity and motor coordination were targeted. The possible mechanism of action was followed by the inhibition of opioid receptors. The right and left sides of the FN were surgically implanted with guide cannulas. Immediately after an intraperitoneal injection of acetic acid (1.00 mL, 1.00%), the first writhing onset latency and the writhing number over 60 min were recorded. Open-field and rotarod tests were applied for general locomotor and motor coordination assessment, respectively. Histamine and dimaprit (H₂ receptor agonist) increased first writhing onset latency, decreased the writhing number and increased falling time from the rod. These effects were prevented by ranitidine (H₂ receptor antagonist) pre-treatment. Significant alterations were not observed by histamine H₁ receptor agonist (2-pyridylethylamine) and antagonist (mepyramine). Naloxone, with no effect on falling time from the rod, inhibited the antinociceptive effects of histamine and dimaprit. Beam break number was not affected by the above-mentioned treatments. Based on the results, it can be suggested that histamine H₂, but not H₁ receptors at the FN might have had an inhibitory role on acetic acid-induced visceral pain and improved motor coordination. The antinociception, but not motor coordination might be mediated by FN opioid receptors.

Abstract Acetamiprid (ACP) belonging to the neonicotinoid family used against wide array of pests in agriculture and domestic purposes. In this study, we evaluated the attenuating effects of ethanolic extract of Mangifera indica leaves (EEMI) in averting reproductive toxicity caused by ACP in male guinea pigs. Thirty male guinea pigs were randomly assigned to five treatment groups (n = 6). Group 1 (T0) received distilled water orally; group 2 (T0-) was given 80 mg kg^-1 of ACP and groups 3, 4 and 5 were treated, respectively, with EEMI at doses of 50, 100 and 200 mg kg^-1 plus ACP. After 90 days, the reaction time, sexual organ weights, sperm count, motility and anomalies, spermatozoa with entire plasma membrane, testicular histology, serum testosterone concentration, testicular malondialdehyde (MDA) level, reduced glutathione (GSH) concentration, testicular superoxide dismutase (SOD) and catalase (CAT) activities were assessed. Co-administration of EEMI significantly reduced the reaction time, sperm anomalies and testicular MDA, SOD and CAT levels compared to the T0- group. Co-treatment of EEMI significantly alleviated sperm count and motility, percentage of spermatozoa with the normal plasma membrane, serum testosterone concentration, accessory sex gland weights, and testicular GSH concentrations. The ACP treatment induced cell membrane degradation in the testis and this effect was prevented with the addition of EEMI. In conclusion, ACP negatively affected the animal reproductive function and induced oxidative stress. The addition of EEMI alleviated the toxic effects of ACP on the reproductive function of male guinea pigs.

Abstract Neuro-immune mediators play an important role in the development of sickness behaviors. In the present study, the effect of captopril on sickness behaviors caused by lipopolysaccharide (LPS) was studied in the rats. The animals were randomized into the following groups: control, sham, 10 mg kg^-1 captopril - LPS (Capto 10-LPS), 50 mg kg^-1 captopril - LPS (Capto 50-LPS), and 100 mg kg^-1 captopril - LPS (Capto 100-LPS). Behavioral tests including open-field (OF), elevated plus maze (EPM) and forced swimming (FS) test were performed, and the serum level of interleukin-6 (IL-6) was assessed. In OF, the number of crossings in the central zone in Capto 10-LPS, Capto 50-LPS, and Capto 100-LPS groups was higher than that of the sham group. In EPM, the open arm entry numbers in the sham group were lower compared to the control group. Furthermore, pretreatment by captopril increased the entries to the open arms. In FS test, the immobility time of the sham group was longer than that of the control group. In Capto 10-LPS, Capto 50-LPS, and Capto 100-LPS groups, immobility was shorter compared to the sham group. In addition, the IL-6 level was higher in the sham group compared to the control group, and treatment with 50 and 100 mg kg^-1 of captopril restored the IL-6 level in comparison with the sham group. Results confirmed that pretreatment with captopril ameliorated LPS-caused sickness behaviors and attenuated IL-6 as an inflammatory marker in the rats.

Abstract Obesity causes many problems such as cardiovascular and chronic kidney diseases. The aim of this study was to evaluate the efficacy of retinoic acid and atorvastatin co-administration in kidneys protection against high-fat diet induced damage. Twenty-five male Wistar rats (200.00 ± 20.00 g) were divided into five groups: 1) Control (standard diet), 2) High-fat diet (cholesterol 1.00%, 75 days), 3) High-fat diet + atorvastatin (20.00 mg kg^-1 per day, orally, on the 30^th day, for 45 consecutive days), 4) High-fat diet + retinoic acid (5 mg kg^-1per day, orally, on the 30^th day, for 45 consecutive days), and 5) High fat diet + atorvastatin and retinoic acid. At the end, blood and tissue samples were collected for biochemical and histological analyses. The results showed that atorvastatin and retinoic acid alone and in combination decreased cholesterol and low-density lipoprotein and increased high-density lipoprotein in high-fat diet. Also, atorvastatin – caused total antioxidant capacity increase and protein carbonyl content decrease the in the renal tissue. Atorvastatin also prevented high-fat diet-induced renal histological injury. Treatment with atorvastatin significantly mitigates high-fat diet-induced renal changes probably due to its potent antioxidant and lipid-lowering effects. The effect of retinoic acid in renal protection in a high-fat diet is far less than that of atorvastatin. The protective effect of the combination of these two agents in the high-fat diet on the kidneys seems to be due to the effect of atorvastatin.

Abstract Vitamin B₁₂ modulates pain at the local and peripheral levels. This study has investigated the effects of intracerebroventricular (ICV) injection of vitamin B₁₂ on themuscle pain. We used diclofenac (cyclooxygenase inhibitor) and naloxone (opioid receptors antagonist) to clarify the possible mechanisms. For ICV injections, a guide cannula was implanted in the left lateral ventricle of the brain. Muscle pain was induced by intramuscular injection of formalin (2.50%; 50 µl) in the right gastrocnemius muscle and the number of paw flinching was recorded at 5-min blocks for 60 min. Locomotor activity was performed using an open-field test. Formalin induced a biphasic pain. Vitamin B₁₂ (1.25, 2.50, 5.00 and 10.00 µg per rat) and diclofenac (12.50 and 25.00 µg per rat) significantly reduced both phases pain intensity. Significant antinociceptive effects were observed after combined treatments of diclofenac (6.25 and 12.50 µg per rat) with vitamin B₁₂ (0.63 and 2.50 µg per rat), respectively. Prior ICV injection of naloxone (10.00 µg per rat) prevented vitamin B₁₂ (10.00 µg per rat) and diclofenac (25.00 µg per rat) induced antinociceptive effects. All the above-mentioned chemicals did not alter locomotor behavior in an open-field test. The present results showed that the cyclooxygenase pathway and opioid receptors may be involved in the central antinociceptive effect of vitamin B₁₂. In addition, opioid receptors might be involved in diclofenac-induced antinociception.

Abstract Testosterone is believed to play a significant role in spermatogenesis, but its contribution to the process of spermatogenesis is not completely understood. Given that extracellular matrix (ECM) facilitates differentiation of spermatogonial stem cells (SSCs) during culture, the present study was conducted to elucidate whether testosterone contribute to the permissive effect of ECM on SSCs differentiation. In experiment 1, testosterone production was measured in testicular cells cultured for 12 days on ECM or plastic (control). In experiment 2, testosterone production was assessed in testicular cells cultured on ECM or plastic (control) and exposed to different concentrations of hCG. In experiment 3, the gene expression of factors involved in testosterone production was analyzed. Testosterone concentration was lower in ECM than in the control group in experiment 1 (p < 0.05). In experiment 2, testosterone concentration was increased in response to hCG in both groups but cells cultured on ECM were more responsive to hCG than those cultured on plastic (p < 0.05). In the experiment 3, qRT-PCR revealed the inhibitory effect of ECM on the gene expression of steroidogenic acute regulatory protein (StAR) (p < 0.05). Nevertheless, the expression of LH receptor was greater in ECM-exposed than in unexposed cells (p < 0.05). In conclusion, the present study showed that inhibiting the expression of StAR, ECM could lower testosterone production by Leydig cells during in vitro culture. In addition, the results indicated that ECM could augment the responsiveness of Leydig cells to hCG through stimulating the expression of LH receptor.

Abstract The parafascicular nucleus (PFN) of thalamus, as a supraspinal structure, has an important role in processing of nociceptive information. In addition, μ-opioid receptor contributes to supraspinal modulation of nociception. In the present study, the effects of microinjection of naloxone (a non-specific opioid-receptor antagonist) and naloxonazine (a specific μ-opioid receptor antagonist) were investigated on morphine-induced antinociception in a rat model of acute trigeminal pain. Right and left sides of PFN of thalamus were implanted with two guide cannulas. Acute trigeminal pain was induced by local corneal surface application of hypertonic saline and the number of eye wipes as a pain index was recorded for 30 sec. Microinjection of morphine at doses of 1, 2 and 4 μg per site significantly (p < 0.05) decreased the number of eye wipes. Alone microinjection of naloxone (4 μg per site) and naloxonazine (1 and 2 μg per site) significantly (p < 0.05) increased corneal pain severity. Prior microinjection of naloxone (2 and 4 μg per site) and naloxonazine (1 and 2 μg per site) significantly (p < 0.05) prevented the antinociceptive effect induced by morphine (4 μg per site). All the above-mentioned chemicals did not alter locomotor behavior in an open-field test. The results of the present study showed an antinociceptive effect of morphine at the PFN level of thalamus. Mu-opioid receptor of the PFN of thalamus may be involved in morphine-induced antinociception.

Abstract Hydrogen sulfide (H₂S) has been shown to protect the gastric mucosa through several protective mechanisms but till now its effect on mRNA expression of sodium bicarbonate cotransporter 1 (NBC1), trefoil factor1 (TFF1) and trefoil factor2 (TFF2) was not investigated. This study was aimed to evaluate the effect of H₂S on mRNA expression of NBC1, TFF1 and TFF2 in rat gastric mucosa in response to gastric distention. Thirty two rats were randomly assigned into four equal groups. They were control (C), distention (D), propargylglycine (PAG)-, and NaHS-treated groups. To evaluate the effect of exogenous and endogenous H₂S on gene expression of NBC1, TFF1 and TFF2, two groups of rats were received H₂S donor, intra-peritoneal NaHS (80 µg Kg^-1), and PAG (50 mg kg^-1), accompanied to stimulate the gastric acid secretion, respectively. Under general anesthesia and laparotomy, a catheter was inserted into the stomach through duodenum for instillation of isotonic saline for gastric distention. Ninety min after beginning the experiment, animals were sacrificed and the gastric mucosa was collected to determine total acid content of gastric effluents and to quantify the mRNA expression of studied genes by quantitative real-time polymerase chain reaction (qRT-PCR). Results showed that A) gastric distention increased the level of mRNA expressions of NBC1, TFF1 and TFF2; B) these levels in NaHS-treated rats were significantly higher than those in Distention group; and C) PAG decreased the expression levels of NBC1 and TFF1. The Findings showed H₂S upregulated gene expression of NBC1, TFF1 and TFF2 in gastric mucosa.

Abstract This study was conducted to evaluate the effect of soy milk on serum 17- β estradiol level and number of neurons in cerebral cortex and hippocampus as well as determination of the ratio of neurons in cortical and hippocampal regions in neonatal ovariectomized rats. Thirty female rats (one day old) were divided into six groups of five. At day 7, ovariectomy surgery was performed in four groups and two other groups were assumed as sham and control groups. Three groups of ovareictomaized rats were fed with soy milk at the doses of 0.75, 1.50 and 3.00 mL kg^-1 per day since they were 14. At day 60, the blood samples were collected to measure the17- β estradiol concentration, and then the brain of rats were prepared for histological studies. The serum 17- β estradiol level significantly increased in ovariectomized rats fed with soy milk compared to ovariectomized rats with no soy milk supplementation. In addition, the results showed that soy milk significantly increased the number of neurons in CA1, CA2 and dentate gyrus regions of hippocampus and granular layer of cerebral cortex in ovariectomized rats, whereas there was no significant change in number of neurons in CA3 zone of hippocampus and molecular, pyramidal and multiform layers of cerebral cortex in ovariectomized rats fed with soy milk. The ratio of cerebral cortex neurons to hippocampal neurons had no significant changes among the experimental groups.

Abstract In the present study, we investigated the effects of histidine and vitamin C (alone or in combination) treatments against isoproterenol (a β-adrenergic receptor agonist)-induced acute myocardial infarction in rats. We used propranolol (a β-adrenergic receptor blocker) to compare the results. Rats were given intraperitoneal injections of histidine (40 mg kg^-1) and vitamin C (40 mg kg^-1) alone and combined daily for 21 days. Propranolol (10 mg kg^-1) was orally administered daily for 10 days (from day 11 to day 21). Myocardial infarction was induced by subcutaneous injections of 150 mg kg^-1 of isoproterenol at an interval of 24 hr on days 20 and 21. Blood and tissue samples were taken for histopathological and biochemical evaluations following electrocardiography recording on day 21. Isoproterenol elevated ST segment, increased heart weight, heart rate, serum activities of aspartate transaminase, lactate dehydrogenase, creatine kinase-MB and heart tissue content of malondialdehyde, and decreased R wave amplitude and superoxide dismutase and catalase activities of heart tissue. Necrosis, edema and inflammatory cells infiltration were observed in myocardial tissue sections. Our results indicated that histidine and vitamin C alone, and especially in combination prevent isoproterenol-induced cardiotoxicity and have similar protective effects with propranolol. Cardioprotective effects of histidine and vitamin C may be associated with their ability to reduce free radical-induced toxic effects.

Abstract The purpose of the present study was to evaluate anti-nociceptive effects of morphine, tramadol, meloxicam and their combinations in rats. Seventy male Wistar rats were divided into seven equal groups and randomly assigned to receive intraperitoneal saline (S) (control group, 1.0 mL kg^-1), morphine (MO) (4.0 mg kg^-1), tramadol (TR) (12.5 mg kg^-1), meloxicam (ML) (1.0 mg kg^-1), tramadol- morphine (TR-MO), meloxicam-morphine (ML-MO) and meloxicam-tramadol (ML-TR) at the same doses. Anti-nociception was evaluated using tail flick latency (TFL) test at 45, 60, 75, 90 and 120 min after drug injection. The TFL was significantly higher in TR and MO groups compared to S group for 90 and 120 min, respectively. No significant change in TFL from baseline values was observed at all time points in ML group. Among rats that received combination of analgesics, those that received TR-MO had significantly greater TFL. There was no significant difference in TFL between ML-TR and ML-MO groups. In conclusion, TR, MO and their combination all provided acceptable anti-nociceptive effects in rats. Meloxicam at the given dosage (1.0 mg kg^-1) did not demonstrate any anti-nociceptive effect when evaluated by TFL test.

Abstract Calcium, through its various channels involves in local, spinal and supra-spinal transmission of pain. In the present study, we investigated the separate and combined treatment effects of verapamil (a calcium channel blocker), morphine (an opioid agonist) and naloxone (an opioid antagonist) on pain in the orofacial region of rats. Orofacial pain was induced by subcutaneous (SC) injection of formalin (50 µL, 1.5%) into the left upper lip side, and the time durations spent face rubbing with epsilateral forepaw were recorded in three min blocks for a period of 45 min. Formalin induced a biphasic pattern (first phase: 0-3 min; second phase: 15-33 min) of pain. Intraperitoneal (IP) injections of verapamil (2 and 8 mg kg^-1) and morphine (2 and 4 mg kg^-1) suppressed orofacial pain. Co-administration of sub-analgesic doses of verapamil (0.5 mg kg^-1) and morphine (1 mg kg^-1) produced second phase analgesia. Both phases of formalin-induced pain were suppressed when an analgesic dose (2 mg kg^-1) of verapamil co-administered with a sub-analgesic dose (1 mg kg^-1) of morphine. The SC injection of naloxone (2 mg kg^-1) alone with no effect on pain intensity, prevented the antinociceptive effects induced by morphine (2 mg kg^-1), but not verapamil (2 mg kg^-1). The obtained results showed antinociceptive effects for verapamli and morphine on orofacial pain. Co-administrations of verapamil and morphine produced antinociceptive effects. It seems that opioid analgesic system may not have a role in the verapamil-induced antinociception.

Abstract In the present study, the effects of intracerebroventricular (ICV) administration of normal saline (control), histamine, mepyramine (a histamine H1-receptor antagonist) and ranitidine (a histamine H2-receptor antagonist) were investigated on the formalin-induced pain in rabbits. Subcutaneous (SC) injection of a formalin (100 μl, 5%) solution into the ventral surface of the right hind paw was performed, and the time durations spent licking and biting the injected paw were measured in 10 min blocks for 1 h. The SC injection of formalin produced a short-lasting (10 min) pain response. The ICV injection of histamine at doses of 25, 50 and 100 μg significantly (P < 0.05) decreased the time duration spent licking and biting the injected paw. Mepyramine and ranitidine, used alone produced no effects. The ICV pretreatments with mepyramine and ranitidine at the same dose of 200 μg significantly (P < 0.05) prevented histamine (100 μg, ICV)-induced antinociception. These results indicate that activation of brain histamine with ICV injection of exogenous histamine produces antinociception. Central histamine H1 and H2 receptors may be involved in the centrally administered histamine-induced antinociception in the formalin-induced pain in rabbits.