Mutagenic evaluation of etintidine (BL-5641), a novel histamine H2-receptor antagonist, using reverse mutation tests in bacteria and forward mutation tests in V79 Chinese hamster cells.

The mutagenic effects of etintidine (BL-5641), a novel histamine H2-receptor antagonist, were assessed using mutation in Salmonella typhimurium, Escherichia coli, and V79 Chinese hamster cells (V79 cells). Etintidine did not increase the revertant colonies in the presence or absence of S9 mix at concentrations from 5 to 5000 micrograms/plate in either of the bacterial tester strains. Etintidine also did not increase 6-thioguanine- and ouabain-resistant colonies in V79 cells in the presence or absence of S9 mix even at 37% cellular survival concentration. There was no evidence that etintidine had any mutagenic activity in any of the tests.