Pharmacological actions of bile salts on the smooth muscle of isolated guinea pig ileum

1) Papaverine-like actions of 5 bile salts, salts, sodium cholate, desoxycholate, dehydrocholate, chenodesoxycholate and ursodesoxycholate were examined with the isolatd guinea-pig ileum and compared by their pD'2values.2) Hemolytic activities of above 5 bile salts were tested using rabbit red cells.3) Desoxycholate and chenodesoxycholate showed strong papaverine-like actions, while dehydrocholate showed an extremely weak activity.4) Bile salts caused no irreversible depression on the acetylcholine response of ileum smooth muscle.5) Surface active agents such as saponin showed no papaverine like actions.6) A fairly good interrelation between the hemolytic actions and the papaverine-like action of bilesalts was observed7) It seems likely that papaverine-like actions of bile salts are unable to be ascribed to their surface active properties, but may be attributed to interactions between the bile salts and the cell membrane components of smooth muscle.