Main description:

The search for a reversible male contraceptive has centered upon the suppression of sperm production or sperm motility. Gossypol, a natural substance extracted from the cotton plant, appears to cause both of these effects. Its ability to reduce spermatogenesis in men is undeniable and has been demonstrated in both large studies in China and a smaller confirmatory study in Brazil. These investiga tions have revealed the remarkable fact that with gossypol, it is possible to separate an effect on the testis' gamete-producing function from an effect on its hormone-producing function. Thus, it is possible to maintain normal testosterone levels and libido while sperm counts (and motility) fall. Because of this unique and important action, gossypol warrants the fullest possible evaluation as a potential male contraceptive. Sheldon J. Segal vii ACKNOWLEDGMENT Lynn C. Landman played a major role in this publication by skillfully editing the manuscripts which were submitted for inclusion in this volume. Janet O'Connell added her efforts in editing, assembling texts and figures and handling final details required for publication. I thank these talented colleagues for their invaluable contributions.

Contents:

and History of Gossypol.- Studies with Human Subjects and Non-Human Primates.- Trial of Gossypol as a Male Contraceptive.- Effect of Gossypol on Human Testicular Function: Evaluation of Seminal and Hormonal Parameters.- Biphasic Action of Gossypol in Men.- Effect of Gossypol on the Fertility of the Male Bonnet Monkey.- Toxicity and Teratogenicity Studies in Animals.- Assessment of Toxicity and Antifertility Efficacy of Gossypol in Male Rats.- The Arrhythomogenic Effect of Gossypol in the Rat Heart.- Gossypol Studies in Male Rats.- Embryonic and Reproductive Toxicity Evaluation of Gossypol.- A Reproduction and Teratology Study with Gossypol.- Mechanism of Action Studies in Vivo.- Effect of Gossypol on Prostatic Androgen Receptors in Male Rats.- Effect of Gossypol on Accumulation of Rhodamine-123 by Sertoli Cell Mitochondria.- Ultrastructural, Biochemical, and Endocrine Studies on the Effects of Gossypol and Its Isomeric Derivatives on the Male Reproductive Tract.- A Solid Phase Radioimmunoassay for Gossypol.- Mechanism of Action Studies in Vitro.- Evaluation of Gossypol's Effect on Bull Spermatozoa in vitro.- Influence of Gossypol on the Motility and Dynein ATPase Activity of Sea Urchin Sperm.- Binding of [14C]-Gossypol by Arbacia Sperm.- Biochemical Studies of Gossypol.- Deactivation of Spermatozoal Fertilizing Capability by Gossypol.- Uptake of 14C-Gossypol by Murine Erythroleukemia Cells: A Model of Unmediated Diffusion for Gossypol Uptake by a Nontesticular Cell.