EFFECT OF ETHANOL ON PHOSPHOLIPID TURNOVER AND CALCIUM MOBILIZATION IN CHICK-EMBRYOS

Effects of ethanol on [H-3]inositol and [C-14]choline incorporation into phosphatidylinositol (PI) and phosphatidylcholine (PC), free intrasynaptosomal Ca2+ ([Ca2+]i) and synaptosomal Ca-45(2+) uptake, were investigated in the brain and heart of 17-day-old chick embryos to which a 10% ethanol solution had been injected on the 3rd day of embryogenesis. In brain synaptosomes, ethanol increased the incorporation of [H-3]inositol and [C-14]choline into PI and PC, increased [Ca2+]i, and decreased Ca-45(2+) uptake. On the other hand, in heart synaptosomal membrane, ethanol decreased the incorporation of [H-3]inositol and [C-14]choline into PI and PC, decreased [Ca2+]i, and increased Ca-45(2+) uptake. Ethanol stimulated in vitro [H-3]inositol and [C-14]choline incorporation into PI and PC in the brain and heart in both the control and ethanol-treated groups. However, addition of ethanol did not affect the release of Ca-45(2+) from the synaptosomal membrane of either organ in either group. Addition of ethanol inhibited Ca-45(2+) uptake in a dose-dependent manner in the brain but not in the heart. In both organs, there was a relationship between phospholipid turnover and [Ca2+]i after ethanol.