Abstract
Mutagenic activity of miporamicin (MPM), a new macrolide antibiotic for animal use, was examined using the reversion test with bacteria, the chromosomal aberration test with mammalian cells in culture and the micronucleus test with rodents.
In the reversion test, MPM exhibited severe growth inhibition effect on the test bacteria but caused no increase of revertant colonies over the baseline levels, alone or in combination with S 9 mixture.
In the chromosome aberration test, MPM induced a medium grade increase of chromosome aberrations at high concentrations, but induced no increase of polyploid cells over the control level.
In the micronucleus test, MPM had no effect on induction of micronucleated polychromatic erythrocyte even at the 1/2 LD50 dose.
From these results, we concluded that MPM has no effect on the induction of point mutations but has a weak clastogenicity which is detectable only by in vitro tests.
