Abstract
Aryl hydrocarbon hydroxylase (AHH) and microsomal cytochromes were measured in tissues of human fetuses aborted by prostaglandins. Cytochrome P-450 concentrations and AHH activity were about 4 times higher in adrenal glands than in liver. AHH was present in testes, ovaries, and vagina and uterus at levels equal to or greater than those in the liver. In lung, kidney, and intestines it was present at levels lower than those in the liver. Mean hepatic AHH and hepatic and adrenal cytochromes P-450 and b5 were not significantly different in prostaglandin and hysterotomy abortuses; mean adrenal AHH was significantly lower in prostaglandin abortuses, but the ranges in both groups were overlapping. Neither fetal sex nor maternal cigarette smoking affected hepatic or adrenal AHH activity or microsomal cytochrome concentrations or difference spectra. Hepatic and adrenal AHH activities were concentrated in microsomes and were correlated with microsomal P-450 content. These findings are consistent with P-450 mediation of AHH in human fetal tissues. The data demonstrate the utility of prostaglandin abortuses for studies of fetal tissue mixed-function oxidase activity and point to the endocrine glands and target tissues in addition to the liver as potential sites for activating chemical carcinogens and cytotoxins in the human fetus.
Footnotes
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↵1 Supported by Grant BC-98 from the American Cancer Society, Grant 1-427 from the National Foundation, Grant 710 from the New York State Health Research Council, and grants from The New York Community Trust and the Revion Foundation.
- Received June 28, 1977.
- Accepted February 24, 1978.
- ©1978 American Association for Cancer Research.