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Background: Formaldehyde is a suffocating gas with a sharp smell which enters the body from different ways and induces tissue damages. With respect to its effects damages on testis and the on testis and spermatozoa, the present study was conducted to determine the effects of formaldehyde on morphometric structure of testis in Balb/C mice.
Materials and methods: In an experimental research, a total of 40 adult mice of the bread Balb/C were selected and assigned in experimental and control groups. For this study 37% formaldehyde was injected intraperitoneally with four doses in a 40-day period. After weighting the mice, the abdomen was opened and the testes were weighted and subjected to morphometric study.
Results: Results showed that there were not significant differences between the experimental group and controls based on testes weight and morphometric structure, however, body weight and the ratio of the weight of two testes to body weight (GSI) did differ significantly. Conclusion: It was showed that despite a significant reduction in body weight following the formaldehyde injection, the weight of testes and their dimensions were not changed.

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Background: Finasteride, a 4-azasteroid compound, is a specific inhibitor of type P 5α-reductase that converts testosterone into 5α-dihydrotestosterone. In the present study, the effects of human dose of finasteride on the number of spermatogenic cells, seminiferous, prostatic and epididymal tubules diameter and thickness of mature NMRI mouse were investigated, both in in vivo and in vitro conditions. Material and methods: In this experimental study, in in vivo condition, 18 mature NMRI mice were divided into 3 groups of 6: control (without treatment), sham (treatment whit physiologic serum) and experimental (treatment with drug). Experimental group was received intraperitoneal injection of 5 mg/kg/day finasteride for 7 days. In in vitro condition, testes, prostates and epididyms of 18 mature NMRI mice were divided into 3 groups of 6: control (fixation with bouin without treatment), sham (treatment with physiologic serum) and experimental (treatment with 5 mg/kg/day of finasteride in culture media for 3 days). Data were analyzed using one way ANOVA and Tukey test by SPSS software. P- value< 0.05 was considered significant.
Results: In in vivo condition, treatment with finasteride did not cause significant reduction in the number of spermatogenic cells, seminiferous tubules diameter compared with control group. But, in in vitro condition, significant decrease was observed. In both conditions, the drug could cause significant decrease in prostatic tubules diameter and thickness compared with control group. Diameter and thickness of epididymis tubules were decreased just in in vitro condition.
Conclusion: Finasteride can act in long-term treatment, high doses and in in vitro condition better than other conditions.

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Background: Methylphenidate or ritalin is one of the brain stimulant drug and used in treatment of attention deficit hyperactivity disorder (ADHD), narcolepsy and situational tachycardia syndrome. In the present survey, the effect of methylphenidate on the liver was studied.

Materials and methods: In this experimental study, a total of 24 male mice were randomly divided into three groups, including one control and two experimental groups. In experimental groups, ritalin was used in the doses of 2 and 10 mg/kg by gavages method for 40 days. At the end of the period and after animals’ euthanasia, the livers specimens were removed. Then, histological changes were studied using a light microscope. Also, blood sera were collected and the hepatic enzymes activity was determined. The data were statistically analyzed by ANOVA test and the p<0.05 was considered as significant.

Results: Administration of methylphenidate in different concentrations resulted in significant reduction of hepatocytes diameters, decrease in nuclei diameters, increase in the size of hepatic sinusoids, and also necrosis and congestion in central vein. Furthermore, in the liver parenchyma belonging to treated groups, the infiltration of mononuclear leukocytes was observed. In the treated groups, the activity of the hepatic enzymes showed a significant increase compared with the control group.

Conclusion: Considering the present findings, it could be suggested to avoid of prescribing of methylphenidate, especially in the patients with hepatic failures.

Keywords: Methylphenidate, Enzyme, Liver, Mouse.