Early effects of gossypol on the testis and epididymis in the rat.

In a previous study we showed that the administration of gossypol to rats for 34 days caused 2 types of modification of the epididymis: (1) the secretion of carnitine and inositol were reduced in the fluid, (2) the spermatozoa lost their motility and showed major morphological changes (head-flagella dissociation). We wished to clarify the early effects of gossypol on the epididymis. Sprague Dawley adult rats (350 g) were forced fed with gossypol at a dose of 25 mg/kg/day for 17 days. After sacrifice, the motility of spermatozoa from the cauda of the epididymis was measured and the morphology of spermatozoa from the caput of the epididymis quantified following electron microscopic examination. Carnitine, inositol and potassium were assayed in the epididymal fluid. No abnormalities of spermatozoa (motility, count, morphology, ultrastructural examination) were observed in the cauda of the epididymis. In contrast, a high percentage (63%) of spermatozoa from the caput of the epididymis were altered (vacuolization and lysis of mitochondria). Biochemical analysis of the fluid revealed no differences between treated animals and controls. Thus it appeared therefore, that after 17 days of gossypol administration, the only abnormality detected in the epididymis involved the spermatozoa from the caput. It is therefore probable that the motility disorders seen in spermatozoa from the cauda of the epididymis at 34 days cannot be explained by alterations of the secretion of fluid but rather by earlier direct lesions of testicular spermatids and/or of spermatozoa from the caput of the epididymis.