[Experimental study on the effect of acetylspiramycin on the fertilized ova].

Growth of fertilized mouse eggs treated with acetylspiramycin (ASPM) for 24 hours in their diplophase and octaplophase was observed morphologically. Changes in function of the fertilized cells in growth process were also examined, determining cell counts, mitotic index, and sister chromatid exchange as indices. These indices were all inhibited after treatment with ASPM. However, it seems that the effect was induced by H2SO4 which was used as solvent rather than by ASPM because growth inhibition and functional changes of cells were also caused by H2SO4. Therefore, it is thought that ASPM, at the concentration of 3-10 microgram/ml, has little effect on the development of fertilized eggs.