Effect of administration of Aroclor 1254 on the activities of hepatic drug metabolizing enzymes in zinc deficiency.
In order to understand the mechanisms of carcinogenesis in zinc deficiency, a study was conducted in experimental animals to investigate the effect of administration of an inducer. After the production of zinc deficiency in NIN/Wistar strain of rats by feeding an egg albumin-starch based diet almost devoid of zinc, the animals were administered a potent inducer of mixed-function oxidases: Aroclor 1254 and various Phase I and Phase II enzymes of drug metabolism like benzo[a]pyrene hydroxylase, microsomal epoxide hydrolase, cytosolic epoxide hydrolase, and cytosolic glutathione-S-transferase studied in liver tissues. Control and pair-fed groups were also run alongside. The results showed that while the activities of various enzymes studied were low in the uninduced basal condition, these activities increased many-fold after induction. This induction was observed not only in the control group, but in the pair-fed and deficient groups as well. These results suggest that the ability to respond to a carcinogenic insult, though initially present in zinc deficiency, may not be adequate to counteract an excess or chronic exposure to carcinogen in the long run.
Jagadeesan
V
V
Food and Drug Toxicology Research Centre, National Institute of Nutrition, Hyderabad, India.
D000818:Animals; D001140:Aroclors / Q000633:toxicity*; D001579:Benzopyrene Hydroxylase / Q000187:drug effects; D001835:Body Weight / Q000187:drug effects; D020111:Chlorodiphenyl (54% Chlorine); D004851:Epoxide Hydrolases / Q000187:drug effects; D005982:Glutathione Transferase / Q000187:drug effects; D008099:Liver / Q000187:drug effects* / Q000201:enzymology; D008297:Male; D008862:Microsomes, Liver / Q000187:drug effects / Q000201:enzymology; D009929:Organ Size / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains; D015032:Zinc / Q000097:blood / Q000172:deficiency*
D001140:Aroclors; D020111:Chlorodiphenyl (54% Chlorine); D001579:Benzopyrene Hydroxylase; D005982:Glutathione Transferase; D004851:Epoxide Hydrolases; D015032:Zinc