Mutagenic evaluation of etintidine (BL-5641), a novel histamine H2-receptor antagonist, using the chromosome aberration test in CHL cells and the micronucleus test in mice.

The mutagenic effects of etintidine (BL-5641), a novel histamine H2-receptor antagonist, was assessed using the chromosome aberration test in CHL cells and the micronucleus test in mice. (1) Etintidine did not show any chromosome aberrations in the presence or absence of S9 mix at any concentration tested. (2) Etintidine did not increase the frequency of micronuclei in polychromatic erythrocytes even at the dose of 50% of the LD50 at single (24 h) and chronological preparation after drug administration.