[Tissue distribution of 9, 3"-diacetylmidecamycin in the pregnant rat and in the rat following repeated administration (author's transl)].

The tissue distribution of 9, 3"-diacetylmidecamycin (MOM) was studied in the pregnant rats and in the rats following repeated administration. After oral administration of MOM (200 mg/kg) in the pregnant rats, the levels in the placenta and in the uterus were 2-3 times higher than that in the blood, however the levels in the amniotic fluid and in the fetus were 1/10-1/20 of the blood levels. After the third administration of MOM in the first day (30 mg/kg p.o./dose, 3 times/day, 4-hour interval), the levels in the liver, kidney, lungs, spleen, salivary glands and thymus were 1.5-12 times higher than that in the blood; the level in the muscle was almost equal to that in the blood; and the levels in the brain were 1/3-1/10 of the blood level. The tissue distribution patterns after repeated administrations were found to be similar to those of the first day administrations.