Effect of gossypol acetic acid on the epididymis: histochemical and scanning electron microscope studies

Rats were treated orally with gossypol acetic acid at 30 or 10 mg/kg daily, 6 days a week, for 8, 12, 14 or 16 weeks. At the end of each treatment regimen, treated rats and an equal number of control rats were killed for histological and histochemical studies. From 8 weeks onward, as a result of the treatment, the tubular lumen of the corpus epididymides became narrowed with thickened pseudostratified epithelium and there was a reduction in the amount of spermatozoa. There was an increase in esterase, alkaline phosphatase, acid phosphatase and ATPase activity. These changes increased in intensity with the duration of treatment. Scanning electron microscopic examinations of the corpus epididymides of rats treated for 16 weeks, compared with those of controls, revealed similar changes, namely, narrowing of the tubular lumen, thickening of the pseudostratified epithelium and reduction in the number of spermatozoa.