Metabolism of estrogens in hepatomas of different growth rates.
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| Abstract |
The activity of estrogen 16alpha-hydroxylase was measured for nine Morris hepatomas of different growth rates and host livers. Activity was measured in the microsomal fraction of the cell (100,000 X g). In the spectrum of hepatomas studied, 16alpha-hydroxylase activity was significantly decreased in parallel with the increase in hepatoma growth rate. The decrease in enzymic activity ranged from 16 to 19% for the slow-growing tumors (Hepatomas 44, 28A, and 9633), 2 to 9% for the intermediate-growing tumors (Hepatomas 38B, 7795, and 5123A), and 0% for the fast-growing tumors (Hepatomas 7288C, 7777, and 42A). Estrogen 16alpha-hydroxylase activity of the liver of tumor-bearing rats differed from that of liver of healthy animals. There was a decrease in enzymic activity ranging from 66% to 90% of normal control rats. The activity level of the host liver did not correlate with tumor growth rate. Stimulation of 16alpha-hydroxylase with phenobarbital showed a 4-fold increase in activity in normal liver and only a 2- to 3-fold increase in host livers. The slow- and intermediate-growing hepatomas showed a 1.2-to 1.4-fold increase in enzyme activity, and no activity or stimulation in the fast-growing hepatomas was observed.
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| Authors | Y J Abul-Hajj, H P Morris |
| Journal | Cancer research (Cancer Res) Vol. 37 Issue 4 Pg. 1083-7 (Apr 1977) ISSN: 0008-5472 [Print] United States |
| PMID | 191175 (Publication Type: Journal Article, Research Support, U.S. Gov't, P.H.S.) |
| Chemical References |
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