Effect of cimetidine on tritiated thymidine incorporation by the stomach, jejunum, colon, liver and spleen of mice.

The administration of cimetidine to mice at a dose of 200 mg/kg and per 24 h inhibits the tritiated thymidine incorporation by the stomach, jejunum, colon and liver and stimulates incorporation by the spleen. These results may furnish an explanation for the rare secondary effects observed in humans. It is also proposed that endogenous histamine may play a role of cytohormone, regulating tissue trophicity.