Changes in rat liver N-hydroxy-2-acetylaminofluorene aryl sulfotransferase activity at early and late stages of hepatocarcinogenesis resulting from dietary administration of 2-acetylaminofluorene.
The ability of 2-acetylaminofluorene (AAF) to mediate a loss in N-hydroxy-AAF (N-OH-AAF) aryl sulfotransferase activity when fed to male Sprague-Dawley rats was examined at early and late stages of hepatocarcinogenesis. Administration of 0.05% AAF in the diet for 1 week caused liver N-OH-AAF aryl sulfotransferase activity to decrease to 15 +/- 5% of that for liver from non-carcinogen-fed rats, and the activity remained low throughout 19 weeks of AAF feeding. When rats were fed AAF diet for 3 weeks, then placed on a control diet, liver N-OH-AAF aryl sulfotransferase activity returned to normal levels within 3 weeks. In contrast, when rats were fed AAF for 19 weeks, then placed on control diet for an additional 10 weeks, little or no recovery of N-OH-AAF aryl sulfotransferase activity was observed in cytosols from whole livers or isolated hyperplastic nodules, respectively. These findings suggest two types of AAF-mediated decreases in sulfotransferase activity: (a) a decrease observed early in the initial stages of AAF feeding which returns to normal levels when AAF is removed from diet, and (b) a persistent decrease in activity following long term AAF administration.
Ringer
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DP
Noble Foundation, Inc., Ardmore, OK 73402.
Norton
T R
TR
Cox
B
B
Howell
B A
BA
D015073:2-Acetylaminofluorene / Q000008:administration & dosage / Q000633:toxicity*; D000083:Acetanilides / Q000494:pharmacology; D000818:Animals; D004032:Diet; D006965:Hyperplasia / Q000201:enzymology; D008099:Liver / Q000187:drug effects* / Q000201:enzymology; D008114:Liver Neoplasms, Experimental / Q000139:chemically induced / Q000201:enzymology*; D008297:Male; D011230:Precancerous Conditions / Q000139:chemically induced / Q000201:enzymology*; D051381:Rats; D011919:Rats, Inbred Strains; D015238:Sulfotransferases; D013466:Sulfurtransferases / Q000037:antagonists & inhibitors / Q000378:metabolism*
D000083:Acetanilides; D015073:2-Acetylaminofluorene; D013466:Sulfurtransferases; C021378:N-hydroxy-2-acetylaminofluorene sulfotransferase; D015238:Sulfotransferases