The Effects of Gossypol on Spermatogenesis and Development of the Eyefluke, Philophthalmus gralli, and Its Chicken Host

Abstract

To determine the effects of gossypol, a male antifertility drug, on the eyefluke, P. gralli, this chemical was administered orally to chickens in long-term and short-term regimens. Gossypol acetic acid (GAA), fed to juvenile chickens from 1 to 35 days, caused a decreased weight gain when compared to controls on untreated feed. An FeSO4 supplement to the GAA-fed chickens provided partial protection from the toxic effects of GAA. Worms from GAA-fed chickens were significantly larger than controls, while those from chickens fed GAA + FeSO4 were intermediate in size. Sperm development in these worms was unaffected by GAA. In a second experiment, GAA was administered either in the feed of the hosts from days 35 to 70 or by capsule from days 63 to 77. Worms were exposed to [3H] thymidine, transplanted to the host's eyes, removed on a timed schedule, and processed for autoradiography to determine the rate of spermatogenesis in both GAA-feed and GAA-capsule groups. Early stages of spermatogenesis in both groups were unaffected by GAA and later stages developed at a slightly faster rate than reported for worms from chickens on untreated feed. Higher frequencies of testicular anomalies were observed in both groups including 3 testes, 1 testis, no testes, fused testes, degenerating testes, ovarian tissue in the testes, deformed sperm, and encapsulated sperm. Testes from chickens in both groups showed a significantly lower weight and no signs of spermatogenesis when compared to control chickens.