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Background & Objective: Many evidence indicated that action of glucocorticoid receptors can modulate anxiety behaviors and these effects probably mediated by nitric oxide (NO) system. Thus, in this study, we investigated interaction between corticosterone and NO on anxiety behaviors in mice in elevated plus maze (EPM).

Materials & Methods: In this experimental study male albino mice (25-30 g) were used. A standard EPM was used to determine anxiety behaviors. Two behavioral measures were used that include of the percentage of time spent in the open arms and the ratio of open arm entries to total entries during 5 min. Animals received IP injection of L-Name 30 mg/kg as an inhibitor or L-Arginine 50 mg/kg as a synthesis of NO or saline 60 min and corticosterone (1, 2.5, 5 mg/kg) 30 min before of evaluation.

Results: Analysis of data indicated that corticosterone at doses of 1 and 2.5, but not 5 mg/kg significantly reduced anxiety behavior in mice (P<0.05). Also pretreatment of L-Name potentiate but injection of L-Arginine had inhibition of corticosterone effects (P<0.05).

Conclusion: This study revealed that glucocorticoid induces anxiolytic effects and these effects probably potentiate by NO inhibitor and reduced by NO synthesis. Therefore, it seems that there are interaction between of glucocorticoid and NO system for control of anxiety behaviors.

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Background & Objective: Addiction to opiates such as morphine is one of major public health problems. It has been shown that in addicted animals, administration of antioxidant agents such as vitamin C can reduce the withdrawal symptoms (WDS). The aim of this study was to evaluate the preventional effect of grapefruit juice (Citrus Paradisi Macf.) on withdrawal symptoms in rats. Materials & Methods: In this experimental study, Sixteen male Wistar rats (250-300g) randomly divided into two groups (n=8). All animals were addicted by intraperitoneal (i.p) injection of morphine (the 1-3 days: 10 mg/kg, the 4-6 days: 20 mg/kg and the 7-9 days 40 mg/kg daily) for 9 days. The first group received 2 ml Citrus Paradisi Macf. orally 1 hour before morphine administration. The sham group received 2 ml of normal saline. Naloxone (10mg/kg, s.c) was administrated 45 minutes after of an additional dose of morphine (40 mg/kg) in the tenth day for withdrawal symptoms inducing. Then withdrawal symptoms such as frequency of wet-dog shaking, teeth chattering, defecation and penis licking were evaluated for 30 minutes. Results: All withdrawal symptoms including frequency of wet-dog shaking, teeth chattering, defecation and penis licking were reduced in the Citrus Paradisi Macf. group in comparison with the sham group significantly (p<0.05). Conclusion: Our results showed that presumably antioxidant activity of Citrus Paradisi Macf. can reduce withdrawal symptoms. Although the exact mechanisms of its effect in brain need to be elucidate.

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Background & Objective: The effects of acute and chronic exposures to opiate drugs on anxiety process are controversial. Acute morphine injection showed the beneficial effects on anxiety. Morphine withdrawal induced severe anxiety response in morphine dependence rats. Whereas, the effects of chronic administrations of morphine on anxiety process are less studied. Furthermore, this study was designed to assess the role of morphine dependence on the level of anxiety in Rat. Materials & Methods: In this experimental study, Twenty male Wistar rats (250-300 gr) were made dependent by chronic administration of morphine in drinking water that lasted at least 21 days. Control groups received only sucrose in their water. This study utilized the elevated plus- maze model to evaluate anxiogenic-like behavior in rats. Four fundamental behavior patterns were recorded for 5 minutes: the time spent on open arms, the number of entries into open arms, stretched-attend posture and defecation. Immediately after test, the locomotor activity of each animal was tested by using an automated activity monitor system. The data were analyzed by independent t-test and two-way analysis of variance (ANOVA). Results: Finding indicated that the time spent on open arms and the numbers of entries into open arms were significantly shorter in morphine dependence group than control group (P<0.05). Also, the numbers of stretched-attend posture and defecation were significantly higher in morphine group (P<0.05). Whereas, there were no significant differences between groups in locomotor activity. Conclusion: This study showed that dependent rats may rapidly predispose anxiogenic- like effects in stressful conditions and without the effect on motor activity.

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Background & Objective: Neural tube defects, growth retardation and nail hypoplasia are most common features of teratogenic effects of carbamazepine. This study was done to determine the effects of carbomazepine on eye development in Mice fetuses. Materials & Methods: In this experimental study 40 BALB/c pregnant Mice were divided into four groups. Experimental groups I and II received 15 mg/kg daily 6-15 GD (gestational days) and 30 mg/kg daily 6-15 GD intraperitoneal of carbamazepine, respectively. All drugs recolved in Tween20. Two control groups received normal saline or Tween 20. Dams were dissected on GD18 and embryos were collected. After observation of eye malformation in fetuses, we employed routine histological processes to stain the samples and also skeletal staining was performed. Results: Calvaria deformations, finger anomalies, brachygnathia and short tail in experimental groups I and II were 7% and 10.8%, 13.3% and 16.6%, 7.8% and 11.7%, 10.2% and 9.2% respectively. Ten of fetuses (8.6%) in experimental group I and nine of fetuses (7.5%) in the experimental group II had eye malformations. Premature opening of one or both eyes with mild to severe exophthalmos occurred in both of the experimental groups. Also, histological examination showed deformed lens, retinal folds with undeveloped layers, corneal fold with absence of surface epithelium. Conclusion: This study revealed that administration of carbamazepine during embryunic period can induce eye malformations in Mice fetuses.

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Background & Objective: In addition to genetic and hormonal effect, various environmental influence on hair growth. For instance, stress can release epinephrine in the blood circulation, and epinephrine can effect on various tissues, especially on skin and hair tissue. Many investigators try to find effective drugs for the hair growth. Because most of these drugs are vasodilator agents, we design present study to determine the local effects of epinephrine administration as a vasoconstrictor agent on growth of hair. Materials & Methods: In this experimental study, 45 Wistar male Rats were divided in three groups, which taking 1.5ml/kg epinephrine, 1ml/kg epinephrine two times/daily for two months and control group which reciving normal salin with same valume for two months respectively. Following observing the macroscopically findings and segregation of the skin, the slide were prepared and the number of hair follicles were examinated. Results: The epinephrine causes degeneration of hair folicule, sebasus gland, and decreasing number of hair folicule in comping with control group (P<0.05). Conclusion: This study showed that the subcutaneous adminstration of epinephrine cause the hair lesions, and this significantly is related directly with the dosage of epinephrine.

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Background & Objective: On the bases of the antiinflammatory, antimicrobial and antioxidant effects of matricaria chamomilla (chamomile) extract. This study was design to determine the effect of topical hydroalcoholic chamomile extract on burn wound healing in albino Rats. Materials & Methods: In this experimental study 30 male albino Rats were randomly divided into 3 equal groups, as sham, control (olive oil) and treatment. Second degree burning was induced in 20% of whole surface area of animal body by diving the back of animal into boiling water for 8 seconds. Animals of control group received no treatment. Animals of olive oil and treatment groups were treated topically by olive oil and hydroalcoholic extract dissolved in olive oil twice a day respectively from the first day of burn induction to complete wound healing. Results: The results showed that there was not significant difference between olive oil and sham groups in all days of experiments. Also there was significant difference in wound healing (p<0.05) between olive oil and treatment groups (62.96±2.70 versus 74.77±2.50) from the day of 20 to the end of experiments. Conclusion: This study showed that the hydroalcoholic chamomile extract has a treatment effect on burn wound healing in animal model.

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Background and Objective: The growing development progress of electronic industries and the increasing use of electrical appliances have led to higher rate of exposure of people to electromagnetic field (EMF). Thus, in this study we investigated the effect of EMF on morphometric indices of epididymis and vas deferen in mice. Materials and Methods: In this experimental study, 30 BALB/c male mice were selected and divided into three control, sham and experimental groups. Experimental group were exposed to 50 Hz, 0.5 mT EMF for 4 hours per days, 6 days per week for 8 weeks while the animal in control and sham groups were not exposed to EMF. After the exposure period, the mice were dissected and left testis was removed and weighted. Samples of epididymis and vas deferen in all groups were taken and were processed for routine light microscopic studies. The diameters of epididymis and vas deferen and the height of epithelial cells in all groups were compared using ANOVA and Tukey tests. Results: The mean diameter of epididymis in EMF group significantly decreased compared to the control group (P<0.05). The mean diameter of vas deferen, the height of epithelial cells in epididymis and vas deferen in EMF groups significantly decreased compared to the control and sham groups (P<0.05). In addition, the weight of testes in EMF group significantly decreased compared to the control and sham groups (P<0.05). Conclusion: This study showed that the EMF exposure for long time could have hazard effect for the male reproductive system by decreasing the diameter of reproductive ducts, the length of epithelial cells and weight of testes.

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Background and Objective: Nowaday many diabetic patients interested in using medicinal herbs to relieve the symptoms of their disease in spite of the availability of synthetic drugs, one of such herbal medicine is green tea, studies about effects of this plant on blood glucose, weight of diabetes is contradict and suitable dosage is not mentioned, thus this study was done to determine the effect of green tea extract on blood glucose and body weight in male induced diabetic Rats. Materials and Methods: In this experimental study 40 wistar male Rats with body weight of 230±20 purchased and kept standard situation subsequently 8 of them considered as normal group and the reminder became diabetic by 50mg/kg IP by streptozotosin. After 2 weeks animals with blood glucose of 200-500 mg/dl were considered as diabetic and divided in 4 groups with 8 animals in each. Then 3 groups of them daily was feed with 50, 100 and 200 mg/kg of extract by feeding tube for 6 weeks, diabetic control group and non-diabetic group also was feed with DMSO10% as well. BS and body weight were assessed at 2nd, 4th, 6th week after daily feeding by different doses of green tea extract, and at last results were analyzed by using student t-test and one way ANOVA. Results: The mean of blood glucose of diabetic control group were significantly higher than non-diabetic group and blood glucose of diabetic groups that was feed with 50, 100 and 200mg/kg of extract was significantly lower than diabetic control group. Body weight of 3 treatment groups were not significantly reduced. Conclusion: This study showed that green tea extract has an antidiabetic effect and suitable dosage of this extract was 100mg/kg.

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Background and Objective: Aloe barbadensis Miller plant was used for treatment of wound healing in traditional medicine. However it has different and sometimes contradictory effects. In this study the effect of Aloe barbadensis Miller gel on skin incisional wound healing in Rat was investigated. Materials and Methods: In this experimental study, forty male wistar Rats were randomly divided into 4 experimental groups including: sham operated, control and two treatment groups. Under deep anesthesia, an incision (3cm, full thickness) was made over skin of the back in Rats. The animals of sham group received no treatment. Control group received topical cold cream twice per day (from beginning to end of experiment) and treatment groups' similarliy received topical Aloe barbadensis Miller gel mixed with cold cream (25% and 75%). For computing the percent of wound healing, the area of wound measured at the days 2, 4, 6, 8, 10, 12, 14 and 16 after beginning of experiments. Results: Aloe barbadensis Miller gel at concentration 25% and 75% significantly improved wound healing at 12th day and 8, 10 and 12th days, respectively in comparison with control group. Conclusion: This study indicated that local administration of Aloe barbadensis Miller gel, accelerate the skin incisional wound healing in Rat. This healing is related to the gel concentration.

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Background and Objective: Low electromagnetic fields (LEMF) are produced by instruments which are works with electricity. This study was done to determine the effect of LEMF on fetal death and bone marrow megakaryocytes in NMRI mouse neonates. Materials and Methods: In this experimental study 64 females’ mice with 6-8 old weeks were used. 2 female mice coupled with one male, and positive vaginal plaque was interpreted as the zero day of pregnancy (GD=0). The pregnant mice were randomly categorized into control and experimental groups. The experimental group were exposed to50HZ, 0.5 mT Low electromagnetic fields on 7-11 days of pregnant period (8h/d). The weight of neonate and death fetus were studied after delivery. The live neonates were dissected on 15th day, and 1 ml of bone marrow was extracted from Tibia and vertebral column, by pressing method. The bone marrow cells suspended in 1:1 IMDM in 15cc (FULCON) tubule and cells was counted with neobar lam. The data were tested by t-student test significance was set up at p<0.05. Results: There was significant differences between the mean weight of one day neonate in cases with controls (P<0.05). The mean of dead fetus in experimental group was higher than controls (P<0.05). The mean of megakaryocytes numbers higher than controls, but this differences was not significant. Conclusion: This study showed that the number of megakaryocytes and fetal death were increased by low electromagnetic fields exposure during pregnancy.

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Background and Objective: The findings of various research indicated that there are different responses to painful thermal stimulation in male and female Rats. In different estrous phases there are different pain thershold border line due to hormonal reaction. Regarding to anti-nociceptive effect of henbane seed. This study was designed to assess the anti-nociceptive afficacy of alcohole extract of henbane seed in different phases of estroes cycle of female Rates. Materials and Methods: In this experimental study 92 female NMRI strain rats weighing 195-220 grams randomly were divided into three, control, experimental and positive groups. Male Rats (n=8) were chosen as control group. To measure the threshold of acute pain, all animals were exposed to the tail immersion test using 52 degree c water. In the experimental group, alcoholic extract of henbane seed (2000 mg/kg) was injected, intraperitoneally, 25-30 minutes before the tail immersion test. Afterwards, in the all of control and experimental groups of female rats the smear samples were taken to determine the sexual phases. In addition, the analgesic effect of henbane was compared with anti-nociceptive effect of sodium salicylate (300 mg/kg). Results: Injection of alcoholic extract of henbane seed, diminished the tail immersion test-induced acute pain in female rats significantly (P<0.05). also, no significant differences of analgesic effect of henbane extract were seen among various phases of estrous cycle in female rats. There is no significant differences of analgesia between henbane and salicylate-treated groups. Conclusion: This study determined that female rats in different phases of estrous cycle have similar pain thresholds and the alcoholic extract of henbane seed is effective in the relief of pain in the various phases of estrous cycle.

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Background and Objective: Biological activity of hydrogen sulphide in smooth muscle of vessel and non-vessel tissue are contradictory. The aim of this study was to examine the effect of hydrogen sulphide on smooth activity of muscle mice jejunum. Materials and Methods: Experiments were performed on mice jejunum and motor activity was recorded from in vitro segments of jejunum ~ 4 cm in length. jejunal segments were mounted horizontally in separate perfusion chamber. Furthermore, using vanilloid receptor 1 deficient mice (VR 1-/-) we tested hypothesis that extrinsic sensory nerves mediated alterations, in motor activity responses in the presence different concentration of of hydrogen sulphide (100-3000 μM). Results: Serosal application of NaHS (as hydrogen sulphide donor) produced a dose-dependent inhibition of motor activity that are not significantly different between VR 1-/- and VR 1 +/+ mice. In the presence of TTX (1μM) NaHS (300µM) caused a reduction in basal tone (19.5%, p<0.05, n=5) and inhibited the contraction evoked by 30µM bethanechol by 55% (n=5, p<0.05). Conclusion: This study showed that hydrogen sulphide is an important motor activity inhibitor in mice jejunum.

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Background and Objective: Unsaturated fatty acids such as turpentine oil can decrease serum leptin level. In regard to this effect and the key role of thyroid hormones and leptin in metabolism. This study was designed to investigate the impact of dietary wild pistachio oil on serum leptin concentration and its relationship with thyroid hormones in experimental hyperthyroidism in male rat. Materials and Methods: In this experimental study thirty white Sprague Dawely adult male rats were divided randomly into the five groups with six rats in each. The first group as a natural control I received only ordinary diet and water during the study period. The second group as a control II received ordinary diet in addition to administration of 12mg Sigma levothyroxine in one liter of water daily for one month. Third, fourth and fifth groups with administration of considered dosage of levothyroxine were received respectively 5%, 10% and 20% concentrations of wild pistachio oil for one month. Blood samples were obtained at 10-day intervals. T4, T3, fT4, fT3 and leptin were measured by RIA and ELISA methods. Serum lipid profiles were measured by enzymatic method. Results: Thyroidal hormones, lipids and leptin level did not show any statistically significant differences between experimental days in the rats of control group I.The serum concentrations of T4, T3, fT4, fT3 in third, T4 in fourth and fifth groups showed significant differences(P<0.05). The serum leptin concentration decreased significantly during the experiment in the third, fourth and fifth groups (P<0.05), but serum lipids did not show any significant differences between various days of experiment. Conclusion: This study showed that the level of T4, T3, fT4, fT3 and HDLc / LDLc ratio at 30th day of study in case groups compaing to controls were decreased and increased, respectively.

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Background and Objective: The application of herbal extract are used as substitution to either drug or complementary medicine. Cinnamomum zeylanicum is one of the important herb which is used for various diseases. This study was done to determine the effects of Cinnamomum zeylanicum (Bark) hydroalcoholic extract on the level of hormones responsible for reproduction in male mice. Materials and Methods: In this experimental study, 48 male adult mice divided in six groups, hydroalcoholic extract of Cinnamon zeylanicum was injected intraperitonealy in different dose (50, 100, 200 and 400 mg/kg/every other day) for 20 days in groups 1-4. Normal saline was injected in only one group as placebo group and the other group was not given any substance and it was considered as a control group. All serum hormones level including FSH, LH and testosterone were measured by Radioimmunoassay (RIA) technique. Results: The concentration of FSH, LH increased following the injected dose of Cinnamon zeylanicum and the most increasing of FSH and LH concentration was in animals which receive 200, 400 mg/kg/every other day of Cinnamomum zeylanicum hydroalcoholic extract. The level of serum testosterone significantly increased in dose of 50, 100 mg/kg/every other day in comparison with control group, too (P<0.05). Conclusion: This study showed that hydroalcoholic extract of Cinnamon zeylanicum elevates the pituitary-gonadal axis hormones.

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Background and Objective: Carbamazepine (CBZ) is an antiepileptic drug that causes significant malformations such as neural tube defects (NTDs), cardiac, skeletal and craniofacial defects if it is consumed during pregnancy. The aim of this study was to evaluate the protective effect of folic acid on prevention of birth defect due to Carbamazepine in Balb/c mice. Materials and Methods: In this experimental study, Sixty Balb/c timed-pregnant mice were divided into 4 experimental and 2 control groups. Two experimental groups received daily intraperitoneal injections of 30 mg/kg (group I) and 60 mg/kg/body weight (group II) of CBZ on gestational days (GD) 6 to 15. Two other experimental groups (group III and IV) received similar doses of CBZ with folic acid supplement (3 mg/kg/day) by gavages route for 10 days before pregnancy and 15 days after GD0 (gestational day 0). Two control groups received normal saline or Tween 20 (polysorbate 20). Dams underwent cesarean section on GD18 and embryos were collected. External examination was done and data concerning malformations, weight and crown- rump of fetuses were collected and analyzed by using SPSS-11.5 software and ANOVA and chi-square tests. Results: The mean weight and crown-rump of the fetuses in both experimental groups I and II were significantly reduced. Also in both experimental groups I and II various malformations were detected such as open eyes, limb defects, scoliosis, facial deformity and NTDs. The mean weight and crown-rump of fetuses in the folic acid treated groups did not show any meaningful differences in comparison with fetuses in experimental groups I and II. Also, meaningful reductions in eye, vertebral, limb and facial defects were seen in fetuses of group III. In experimental group IV, reduction of vertebral and limb defects were observed. Conclusion: This study showed that consumption of folic acid (3 mg/kg/body weight) before and during pregnancy can reduce birth defects due to CBZ in Balb/c mice fetus.

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Background and Objective: Several investigations have indicated the antinociceptive, anti-inflammatory, antipyretic effects and smooth muscle relaxant activity of Cassia species. This study was done to determine the effect of Cassia fistula on sleeping time and the level of anxiety in mice. Materials and Methods: In this experimental study, 80 male albino mice (25-30 g) randomly allocated in 8 groups. For measuring the sleeping time we used the Angle method and animals were divided into three experimentals (250, 500 and 1000 mg/kg) and one control group. For evaluating of anxiety levels, animals randomly were divided into three experimentals and one control group, and elevated plus maze (EPM) model was used. The evaluation of anxiety indices included number and percent of time spent in open arm. Different doses of the aqueous extract of Cassia fistula (250, 500, 1000 mg/kg IP) were injected intraperitoneally to the treated groups. Controls were recived 10 ml/kg/BW normal saline intraperitoneally in both methods. Results: The extract of Cassia fistula (250, 500 and 1000 mg/kg) significantly increased sleeping time [F (3, 39)=23.19, P<0.05]. Also open time [F (3,39)=15.55, P<0.05] and the number of open arm entries [F (3, 39)=24.21, P<0.05] were significantly in doses (250mg and 500 mg) were singnificantly more than control group, respectively (P<0.05). Conclusion: This study showed that the aqueous extract of Cassia fistula fruit incerase the sleeping time and deereasing level of anxity in mice.

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Background and Objective: Zinc is an essential ion for living and inter the body from different sources. Since Zn⁺⁺ interfere on many cellular process such as biological function such as calcium chanalls, this study was designed to investigate the effect of oral ZnCl₂ on glucose, Insulin, lipoproteins and liver enzymes in male Rats.

Materials and Methods: This experimental study was performed on 48 of Wistar-Albino male Rats randomly allocated into three exprimental and one control groups. Exprimental groups received 50 mg/l, 100 mg/l and 200 mg/l ZnCl₂ in drinking water daily for four weeks but the control group received tap water. After four weeks, animals were anesthetized, sacrificed and blood samples were collected. Glucose, insulin, lipoproteins, aspartat amino transferase (AST) and alanine amino transferase (ALT) were measured. Data were analyzed by SPSS-11, ANOVA and Tukey-tests.

Results: The mean±SD of Cholesterol in group D (85.7±3.2), HDL in groups B, C, D (66.1±2.7, 67±2.18, 68.83±2.69 mg/dl) and LDL in groups B, C, D (2.8±0.9, 14.6±6.3, 13.4±2.8 mg/dl) respectively were significantly decreased compared with Cholesterol (125.5±4.9 mg/dl), HDL (80.5±3 mg/dl) and LDL (30.3±3.2 mg/dl) in group A. Mean±SD of glucose, insulin, triglyceride and liver enzymes did not show any differences among the groups.

Conclusion: This study showed that ZnCl₂ added on drinking water reduce serum lipoproteins in male Rats.

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Background and Objective: The food additives, like sodium and potassium benzoate are used in many food products and drugs to prevent the growth of yeast and molds. There is no report about the histopathological effect of potassium benzoate. Placenta, has a critical role in embryonic development therefore this study was set up to evaluate the effects of potassium benzoate on placenta of BALB/c mice.

Materials and Methods: 45 BALB/c female mice were allocated into two experimental (1, 2) and one control groups. Experimental groups received daily intraperitoneal injection of 280 and 560 mg/kg/body weight of potassium benzoate and control group received normal saline. All injections were done during 10 days before mating and 5^th to 16^th of gestational days (GD). In GD 18 all placenta were removed via cesarean section. Macroscopic studies for morphological abnormalities were done and after measuring of placental weight and diameter, for microscopic studies the specimens were fixed and tissue passage were done. Tissue sections were stained with hematoxylin-eosin and histopathological changes were studied. Weight, diameter and percentage of agenesis of placenta in all groups were gathered. Data analyzed with using
SPSS-11.5, ANOVA and Tukey tests.

Results: The mean weight and diameter of the placenta in both experimental groups 1 and 2 were significantly decreased compared to control group. Also atrophy of placenta in the experimental groups was increased significantly compared to the control group (P<0.05). Comparison of weight and diameter between groups 1 and 2 was not significant. Percentage of placenta agenesis in the experimental groups was increased significantly compared to the control group (P<0.05). Massive hemorrhage in labyrinth zone, fetal and maternal zones were seen in both experimental groups.

Conclusion: This study showed that exposure of potassium benzoate during mice pregnancy cause morphological and histopathological changes of placenta, including decrease of weight and diameter, agenesis, hemorrhage and tissue disorders.

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Background and Objective: Neurons are injured under physical, chemical and pathological conditions. The effects of injuries in peripheral nervous system returns as retrograde to the cell body of neurons in central nervous system and causes brain and spinal degeneration. This study was done to evaluate the effect of aquatic extract of Cannabis sativa leaves on degeneration of alpha motoneurons in spinal cord after sciatic nerve compression in Rats.

Materials and Methods: This experimental study was carried out on thirty two male Wistar rats, weighing 300-350 grams. Animals were divided into four groups each consisting eight members A: control, B: compression, C: compression + treatment with 25 mg/kg aquatic extract, D: compression + treatment with 50 mg/kg aquatic extract. In order to induce compression in B, C and D, after cutting the right thigh muscle, Sciatic nerve of thigh was exposed to compression for 60 seconds using locker pincers. The first extract injection was done intraperitoneally immediately after compression and the second intera peritoneal injection was done 7 days later. 28 days after compression, the Lumbar spinal cord were dissected, fixed and stained with toluidine blue. The density of alpha motoneurons was measured using dissector and stereological methods. Data was analyzed with using Minitab-13 software, ANOVA and Tukey tests.

Results: Neuronal density was 611.5±34.2 and 1633.4±30.7 in compression and control groups respectively (P<0.001). There was a meaningful statistical increase in neuronal density of group C (1278.6±28.1) in comparing compression group (P<0.001). The neuronal density in group (D) (1549.8±87.7), significantly increased in comparison with group (B) (P<0.001).

Conclusion: This study showed that aquatic extract of Cannabis sativa leaves increases the density of alpha motoneurons in spinal cord after sciatic nerve compression in Rats. The increase in neuronal density is relevant to the amount of extract used.

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Background and Objective: Morphological alterations of hippocampus and dentate gyrus due to opium were reported in humans and animals. Also other evidences have shown that astrocytes actively participate in synaptic plasticity. This study was done to determine the conditioning place preference (CPP) on astrocytes number of Rat dentate gyrus by immunohistochemical technique.

Materials and Methods: In this experimental study, 48 male Wistar Rat weighted average 220-250 g were used. For behavioural tests, Rats divided into eight experimental groups. The Rats were received morphine at different doses (2.5, 5, 7.5 mg/kg) for three days by subcutaneous injection and sham groups, received saline dose (1 mg/kg) and then CPP test in them were investigated. 48 hours after behavioural testing animals were decapitated under chloroform anesthesia and their brains fixed and after tissue processing, slices stained with immunohistochemistery techniques. For morphometric study PTAH staining of astrocytes was used.

Results: The most dose responses of morphine was observed in 7.5mg/kg. The number of astrocytes in the controls (20.627±6.129) was similar to control-saline group (17.339±4.71). This difference was not significant, while the difference in the number of astrocytes in control group with morphine-treated experimental groups was significant (P<0.05).

Conclusion: We concluded that the phenomenon of conditioned place preference induced by morphine can cause a significant increase in the number of astrocytes of sham and experimental groups compared to controls.