This application, which deals with the effects of alcohol on the liver, requests the conversion of an individual research grant, which has been funded for 25 years to a Program Project. The four individual projects are concerned with (1) the effects of ethanol on signal transduction in intact hepatocytes, (2) mechanistic studies of the effects of ethanol on signal transduction in membrane systems, namely turkey erythrocytes and isolated liver plasma membranes, (3) the effects of ethanol on the interaction of liver cell membranes and extrinsic membrane-associated proteins, involved in signal transduction, and (4) the molecular characteristics of ethanol-hepatocyte membrane interactions. In these projects, we will study the effects of ethanol in vitro and of chronic ethanol feeding on membrane-associated parameters in the hepatocyte, including (but not restricted to) ligand-receptor coupled CAMP and phosphoinositide signal transduction systems, homologous and heterologous desensitization produced by ethanol, alterations in the interactions of phospholipase A2 and protein kinase C with liver cell membranes, and differential binding of ethanol in hepatocyte membranes in naive and chronically intoxicated animals, to distinguish specific from bulk effects. Techniques include ESR, NMR, time-resolved fluorimetry, digital imaging fluorescence microscopy, laser confocal microscopy, and preparative and analytical HPLC. The overall goal of the integrated biochemical and biophysical studies in this program project is a deeper insight into the mechanisms of ethanol-induced liver injury.
