A structural and cytochemical study of the effects of gossypol on the epithelial cells of the guinea-pig seminal vesicle.

Gossypol acetic acid, given to guinea-pigs at a concentration of 10 mg/kg daily for up to 7 weeks, exerted an inhibitory effect on the secretory activity of the glandular cells of the seminal vesicles. The diminished secretory function was associated with a decrease in thiamine pyrophosphatase (TPPase) (EC 3.6.1.6) activity in the luminal border and the Golgi cisternae. There was no increase in cytoplasmic filaments, and mitochondrial damage was not observed. The most striking effect was on the basal lamina, where the lamina densa increased significantly in thickness, while the lamina lucida decreased marginally in thickness. This was coupled with an increase in proteoglycan content on both sides of the lamina densa. It would appear that gossypol reduces the luminal secretory function on the one hand, while it increases the basal secretory activity on the other, thus modifying the structure of the basal lamina. The functional significance of these changes remains unknown.