Infection with Trypanosoma brucei potentiates the antifertility effect of gossypol, especially in the protein-malnourished male rat.

Reproductive parameters were investigated in gossypol-treated male rats that had been infected experimentally with Trypanosoma brucei and then place on one of two diets of differing (low and normal) protein content. The endpoints assessed were reproductive organ weights, semen epididymal sperm counts, serum testosterone and histological, stereological and histomorphometric evaluation of the testis and accessory reproductive organs. Most of the parameters studied were lowest in the protein-malnourished, gossypol-treated, trypanosome-infected animals, when compared to those obtained from the corresponding animals that were only gossypol-treated or trypanosome-infected. Mean testicular size and the diameter and the total length of seminiferous tubules were especially reduced, indicating that the overall volume of the seminiferous epithelium in these animals was smaller. These findings suggest that reproductive capacity could be impaired in protein-malnourished, trypanosome-infected animals fed on gossypol-containing products, even when there are no obvious clinical signs of disease. This could translate into increased production costs in a farm enterprise. Screening for haemoparasitism would also seem to be worthwhile prior to evaluation and/or use of gossypol (or perhaps other potential contraceptives) in human subjects, especially in communities that are confronted with severe food shortages.