||Quantitative Image Cytometry of Hepatocytes Expressing Gamma-Glutamyl Transpeptidase and Glutathione S-Transferase in Diethylnitrosamine-Initiated Rats Treated with Phenobarbitol and/or Phthalate Esters.
Carter, J. H. ;
Richmond, R. E. ;
Carter, H. W. ;
Potter, C. L. ;
Daniel, F. B. ;
||Health Effects Research Lab., Cincinnati, OH. Genetic Toxicology Div. ;Wood Hudson Cancer Research Lab., Newport, KY. ;Northern Kentucky Univ., Highland Heights. Dept. of Biological Sciences.
Glutathione transferases ;
Phthalate esters ;
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Image cytometry was used to quantify the volume of liver tissue expressing two widely accepted biochemical markers of neoplasia, gammaglutamyl transpeptidase (GGT) and the placental isozyme of glutathione s-transferase (GST-P). Rats were treated with the hepatocarcinogen, diethylnitrosamine (DENA) alone or combined with phenobarbital (BP). Other groups of rats received either diethylhexylphthalate (DEHP) or di-n-octylphthalate (DOP) in their diets for 26 weeks. GGT expression was detected diffusely throughout the liver parenchyma in several treatment groups so that any enhanced expression in AF and N was not apparent. GST-P was detected only in AF and N. GST-P may represent a second genetic alteration as GST-P(+) AF and N also expressed GGT but not the reverse. By using the stereologic Principle of Delesse (area%=volume%) and the known liver weight, the grams of tissue expressing either marker was quantified. The peroxisome proliferator, DEHP, inhibited expression of GGT or GST-P in livers of either DENA treated or DENA+PB treated rats. With GST-P, the reduction was correlated to a reduced number of AF and N.