Abstract
Bile acid is used clinically as a gallstone dissolving agent, but it possesses some side effects, such a hepatotoxicity by its surface activity. Various surface-active agents may obstruct the functioning of human isolated hepatocytes ; and biphasic effects such as protection of hypotonic hemolysis in lower concentrations and promotion of hemolysis in higher concentrations are seen. The author this time conducted a study on four kinds of bile acids : Cenodeoxycholic Acid (CDCA), Deoxycholic Acid (DCA), Ursodeoxycholic Acid (UDCA) and Cholic Acid (CA), by observing, firstly, effects on their membranes of leakage of glutamic oxalacetic transaminase (GOT) and lactic dehydrogenase (LDH) from isolated rat hepatocyte ; secondly, by their biphasic effects, such as those found in hypotonic hemolysis, using erythrocytes of rats ; and, thirdly, through surface activities. The author also conducted a simi lar study on Alkyltrimethylammonium Salts-Decyltrimethylammonium Bromide (C10), Dodecyltrimethylammonium Bromide (C12), Tetradecyltrimethylammonium Bromide (C14) and Hexadecyltrimethylammonium Bromide (C16) -which are all surface-active agents. The results showed a close correlation between membrane effects and those of surface-active agents. These membrane effects changed according to the number and place of hydroxy group in the hydrophilic region in the case of bile, and according to the length of the Alkyl chain in the hydrophobic region in the case of Alkyltrimethlammonium Salts. The order of strength for the bile acids was CDCA≥DCA>UDCA≥CA and in the Alkyltrimethylammonium Salts was C16≥C14>C12>C10. Surface activities seem to be related to the occurrence of hepatic damage and, therefore, they should be studied more thoroughly as to the membrane effects of agents.
