Effects of cocaine on testicular structure in the rat.

The effects of hourly injections of moderate doses of cocaine hydrochloride (0.5 and 10 mg/kg body weight) over 5 h on testicular structure and testosterone levels were studied in male Wistar rats. Cocaine produced a rapid disruption of spermatogenesis; the number of normal seminiferous tubules declined to 50% (low dose) and 40% (high dose), and regressive tubules (tubules with cellular degeneration, cell sloughing, or abnormal cell structures) increased to 50% (low dose) and 60% (high dose) after treatment with cocaine. The mean tubular diameter, the surface occupied by the tubules, and the volume of seminiferous tubules per pair of testes were significantly reduced (P less than 0.01) after both doses of cocaine. Cocaine produced ultrastructural changes in the cells of the seminiferous epithelium (spermatogonia, spermatids, and Sertoli cells) including vacuoles, abundant lipid droplets, and giant mitochondria. Lower doses of cocaine increased serum testosterone levels (P less than 0.025) while higher doses did not. These findings indicate an acute effect of cocaine on the structure of the rat testis.