Normal and preneoplastic hepatocytes were isolated from the untreated liver and carcinogen-induced hyperplastic liver nodules of rats, respectively. Phalloidin sensitivity of the 1-hour cultured cells decreased in the presence of cholesteryl hemisuccinate (CH). This was seen more markedly in the order of peneoplastic hepatocytes positive in gamma-glutamyltransferase (GGT), the preneoplastic cells negative in GGT, GGT-positive normal hepatocytes, and GGT-negative normal hepatocytes. Coexistence of phosphatidylcholine and CH inhibited the CH-inducible decrease completely in GGT-negative normal hepatocytes and partially in the normal cells positive in GGT, but failed to recover the decrease in both GGT-negative and positive preneoplastic hepatocytes. These phenomena are suggested to be ascribed to the differences of the cell membrane fluidity among these cells
