title: Enhancement of plasma alpha-fetoprotein, as measured by sandwich-type radioimmunoassay, and induction of gamma-glutamyl transpeptidase-positive hepatic cell foci in rats fed benzo[a]pyrene.
abstract: Male Fischer rats were fed semipurified diets containing 0, 1, 100, and 1000 ppm benzo[a]pyrene (BaP) for 6 or 13 wk. Plasma samples were assayed for alpha-fetoprotein (AFP) by a new sandwich-type radioimmunoassay (RIA) utilizing a special controlled porous-glass solid phase. This procedure is described in detail. Significant AFP elevation (p less than or equal to 0.01) was observed in the highest BaP treatment group after 5 wk of treatment. The 1 and 100 ppm Bap groups exhibited no AFP elevation throughout the study. Liver sections from the 1000 ppm groups had discrete gamma-glutamyl transpeptidase (GGT)-positive foci 10-20 cells in diameter by the 6th wk. GGT-positive foci were not evident in liver sections from the other treatment groups. Thus a high level of dietary BaP appears to rapidly alter rat liver cells, indicating hepatic neoplasia.
mesh_terms: D000818:Animals; D001564:Benzo(a)pyrene; D001580:Benzopyrenes / Q000494:pharmacology*; D001835:Body Weight; D005260:Female; D008099:Liver / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D011247:Pregnancy; D011863:Radioimmunoassay / Q000379:methods; D051381:Rats; D013997:Time Factors; D000509:alpha-Fetoproteins / Q000378:metabolism*; D005723:gamma-Glutamyltransferase / Q000096:biosynthesis*
chemical_list: D001580:Benzopyrenes; D000509:alpha-Fetoproteins; D001564:Benzo(a)pyrene; D005723:gamma-Glutamyltransferase