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Background and Objective: Attention deficit hyperactivity disorder (ADHD) is the most common in psychology and Methylphenidate hydrochloride (MPH) is one of the most frequently prescribed pediatric medicine. This study was done to determine the effect of Methylphenidate hydrochloride on ovarian and pituitary gonadotropin hormone in peripubertal mice Materials and Methods: This experimental study was done on 40 preipubertal female mice (BALB/c) with three weeks age and approximate 12-15 gram. The mice were allocated randomly in one control and three experimental groups, designated as I, II and III. Animals in group I, II and III were received by gavage Methylphenidate hydrochloride with 2, 5 and 10 mg/kg body weight for six days, respectively. At the end of experiment body weight, serum estrogen, progesterone and pituitary gonadotropins were measured. Morphometric and histopathological evaluation of ovary were examined. Data were analyzed using SPSS-17, ANOVA and Tukey tests. Results: The body weight and ovary dimensions of animals in experimental groups were reduced significantly in comparison with control (P<0.05). Abnormal cells, structural alternations of granules cells and follicular growth abnormality were observed in experimental groups I and III in compare to control group. A significant reduction of estrogen, in group I, progesterone levels in group I and III were observed in comparison with the controls (P<0.05). Conclusion: This study showed that the Methylphenidate hydrochloride administration induces the reduction of body weight, ovary dimensions and hormones.

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Background and Objective: Nicotine is an addictive substance and Ritalin is a medicine which has been prescribed for treatment of hyperactivity / attention deficit disorder (ADHD). This study was done to evaluate the effect of Ritalin and nicotine and combination of Ritalin and nicotine on daily sperm production and epididymal sperm reserve in mice. Methods: In this experimental study, 120 adult male BALB/c mice were randomly allocated into one control group and 11 experimental (treatment) groups. Animals, in the first, second and third treated groups were received nicotine at the doses of 100, 200 and 400 microgr/kg/bw, respectively. Mice in fourth and fifth treated groups were received Ritalin at doses of 2 and 10 mg/kg/bw, respectively. Animals in sixth and seventh treatment groups were received nicotine in 400 microgr/kg/bw and Ritalin in 2 and 10 mg/kg/bw and in eighth and ninth groups, nicotine at dose of 200 microgr/kg/bw and Ritalin at doses of 2 and 10 mg/kg/bw, respectively. Animals in tenth and eleventh treated groups were received nicotine as dose of 100 microgr/kg/bw and Ritalin at doses of 2 and 10 mg/kg/bw, respectively. Ritalin and nicotine were administrated orally for 40 days. At the end of study, daily sperm production and epididymal sperm reserve were measeared. Results: The daily sperm production was significantly reduced in the groups with high consumption doses of nicotine and different doses of Ritalin and the majority of groups which used the combination of Ritalin and nicotine (P<0.05). The epididiymal sperm reserve was significantly increased in experimental groups of 8, 9, 10 and 11 which were received the combination of Ritalin and nicotine in different doses (P<0.05). Conclusion: The combination of Ritalin and nicotine reduces daily sperm production and it incereases epididiymal sperm reserve in adult BALB/c mice.