Gossypol-induced alterations of aminophospholipid composition in human sperm.

Abstract

Gossypol-induced alterations of aminophospholipid composition in human sperm were observed and the effects of some factors on these alterations were investigated. The alterations of aminophospholipid composition of human sperm induced by gossypol included a progressive decrease in the levels of phosphatidylethanolamine (PE) and phosphatidylserine (PS) when gossypol concentrations ranged from 5-500 mumol/L, and a progressive increase in the level of (LPE) at lower gossypol concentrations (5-50 mumol/L). The conversion of PE into lysophosphatidylethanolamine (LPE) was strongly enhanced by Ca2+ and inhibited by 0.5 mmol/L EDTA, while PMSF, NEM, iodoacetamide and Zn2+ had no effect. This conversion was weaker in sperm with stripped surface proteins than in normal sperm. In addition, three surface proteins (MW 80, 60 and 40 kD) were fixed on the plasma membrane by gossypol treatment. The significance of gossypol action and the possibility that sperm PLA2, PE and some surface proteins might play an important role in the physiological acrosome reaction of human sperm, as well as in oocyte penetration, are discussed.