Effect of metronidazole on spermatogenesis, plasma gonadotrophins and testosterone in rats

Metronidazole and its derivatives have both antiprotozoal and anti bacterial effects. The reproductive toxicity of metronidazole has been observed in some studies. The aim of this study was to determine the detrimental effects of metronidazole on spermatogenesis and testicular androgenesis in male adult rats. Eighteen male Wistar rats (70-90 days old) were randomly divided into three groups. Animals in group I (Control group) were administered with the water only. Animals in groups II and III were administered with metronidazol at the doses of 200 or 400 mg/kg/day for 60 days. Quantitative analysis of spermatogenesis was carried out by counting the relative number of each variety of germ-cells at the stage VII of the seminiferous epithelium cycle, i.e. type-A spermatogonia (ASg), preleptotene spermatocytes (pLSc), and step 7 spermatids (7Sd). Plasma follicle-stimulating hormone (FSH), luteinizing hormone (LH) and testosterone were measured by radioimmunoassay (RIA). In groups II and III, there was a significant decrease in the testes, accessory sex organ weights, plasma concentrations of LH, FSH and testosterone with massive degeneration of all the germ cells at stage VII. Our data concluded that metronidazole has a suppressive influence on spermatogenesis and sex hormones in rats.