Pattern of transplacental penetration of 7,12-dimethylbenz(a)anthracene and its distribution in the fetal organs in man

Abstract

On the 21st day of pregnancy 7,12-dimethylbenz(a)anthracene (DMBA) was injected into female rats in a dose of 15 mg/kg and its concentration in the liver of the pregnant rats, the placenta, and the fetus was determined by a fluorescence-spectral method. The maximal concentration was rapidly reached (after 10–15 min) in the liver of the pregnant rats (45 mg/kg) and placenta (6.3 mg/kg), but more slowly (after 1 h) in the tissues of the fetus (2.4 μg/kg). Clearance of the carcinogen from all the tissues took place relatively slowly (in about 5 h). DMBA was shown to be irregularly distributed in the different organs of the fetus 1 h after its injection into the pregnant rats: maximally in the fetal liver, minimally in the carcass, compared with its concentration in other organs (kidneys, lungs, brain, intestine). The results do not correlate with data showing the development of tumors predominantly in the kidneys and nervous system of rats following transplacental exposure to DMBA.