Effect of DDT on hepatic mixed-function oxidase activity in normal and vitamin A-deficient rats.
Feeding of vitamin A-deficient diet to male weanling rats for 10 weeks resulted in significant decrease in the body weight and marked reduction in the hepatic vitamin A content. The levels of hepatic phase I microsomal enzymes cytochrome P-450, cytochrome b5, aminopyrine N-demethylase and arylhydrocarbon hydroxylase were found to be substantially reduced by vitamin A-deficiency. Also, the activity of phase II microsomal UDP - glucuronyl transferase enzyme was significantly decreased in deficient animals. Following repeated oral administration of DDT (15 mg/kg/body wt/day) for 21 days, the phase I microsomal enzymes were induced to a greater extent in controls as compared to deficient animals. UDP - glucuronyltransferase remained insensitive to DDT induction. The results imply that the capacity for induction of the hepatic mixed-function oxidase enzyme system is impaired in deficient animals concurrently exposed to DDT.
Gupta
P H
PH
Department of Gastroenterology, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
Mehta
S
S
Mehta
S K
SK
D000818:Animals; D003634:DDT / Q000494:pharmacology*; D004790:Enzyme Induction / Q000187:drug effects; D008297:Male; D008862:Microsomes, Liver / Q000187:drug effects / Q000201:enzymology*; D006899:Mixed Function Oxygenases / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D014802:Vitamin A Deficiency / Q000201:enzymology*
D003634:DDT; D006899:Mixed Function Oxygenases