Segmental aplasia of the mitochondrial sheath and sequelae induced by gossypol in rat spermatozoa.

The effect of gossypol upon organelles of rat sperm was investigated by light and electron microscopy. The drug was administered s.c. for 2 to 30 days at 20 mg/kg BW/day. Sperm from the testis, caput, corpus, and cauda epididymis were examined at regular intervals, during and after treatment, for periods extending up to 70 days. The drug induced a specific effect in the sperm tail. It consisted of segmental aplasia of the mitochondrial sheath observed in high incidence in testicular and epididymal sperm. This primary lesion, in the authors' view, predisposed a development of secondary lesions as sperm advanced along the epididymis. Secondary lesions included bulging, dislocating, fraying, or breaking of axial fibers, bending or breaking of the tail, and decapitation. A minimum of 3 days of treatment was necessary to produce an effect above control values, while 9 days or longer induced lesions in almost all sperm. Motility ceased with 30 days of treatment. Fertilizing capacity was inversely related to the increase and decline of lesions.