Methylmercury- and mercuric-chloride-induced alterations in rat epididymal sperm.

Four-week-old male albino rats weighing 70 +/- 5 g were treated intraperitoneally daily with 0, 5 and 10 micrograms methylmercuric chloride (MMC)/kg or 0, 50 and 100 micrograms mercuric chloride (MC)/kg body weight, respectively, over a period of 90 days. Studies were carried out a intermittent intervals, i.e. on days 0, 15, 30, 60 and 90 of the experiment. Gradual decrements in body and epididymal weights were observed from day 30 onwards in both the MMC- and MC-treated groups. Morphological deformations of epididymal epithelium were noted from day 30 onwards in the mercurial-treated groups. MMC treatment caused severe degeneration of the epididymal epithelium on days 60 and 90 in comparison to MC treatment. Total sperm count was significantly less in the MC-treated groups, while motile sperm count was affected most in the MMC-administered groups. The frequency of sperm abnormality increased consistently at both doses of mercurial treatment over a period of 90 days. Maximum sperm abnormality among the treated groups was noted in the groups given 10 micrograms MMC/kg. The observations revealed that MMC and MC have variable potency to alter epididymal structure and the sperm.