Effect of cadmium in vitro on benzphetamine-N-demethylation and ethoxyresorufin-O-deethylation in rats of different age.
The in vitro influence of CdSO4 on the liver microsomal benzphetamine-N-demethylation and ethoxyresorufin-O-deethylation activities in male Wistar rats/age 10, 30, 60 and 240 days/as well as the type of inhibition were studied after phenobarbital or beta-naphthoflavone pretreatment. Both reactions were inhibited by CdSO4 in dependence on concentration in all age groups. After phenobarbital pretreatment the inhibition of N-demethylation was slightly pronounced in 10-day old rats. In 10 and 30-days old rats the type of inhibition was competitive while in 60 and 240-days old rats a non-competitive type of inhibition was observed. O-deethylation of ethoxyresorufin was inhibited also in 10-day old rats, the inhibition type was non-competitive in all age groups. After beta-naphthoflavone pretreatment N-demethylation was inhibited competitively in all age groups. The inhibition of O-deethylation was more pronounced in 30-day old rats, in other age groups the inhibition was weak but concentration dependent. The type of inhibition was noncompetitive for all age groups studied.
D000375:Aging; D000818:Animals; D001571:Benzoflavones / Q000494:pharmacology; D002104:Cadmium / Q000494:pharmacology*; D019363:Cytochrome P-450 CYP1A1; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D004790:Enzyme Induction / Q000187:drug effects; D066298:In Vitro Techniques; D007700:Kinetics; D008297:Male; D010088:Oxidoreductases / Q000037:antagonists & inhibitors*; D010089:Oxidoreductases, N-Demethylating / Q000037:antagonists & inhibitors*; D010634:Phenobarbital / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D019324:beta-Naphthoflavone
D001571:Benzoflavones; D002104:Cadmium; D019324:beta-Naphthoflavone; D003577:Cytochrome P-450 Enzyme System; D010088:Oxidoreductases; D019363:Cytochrome P-450 CYP1A1; C019781:benzphetamine N-demethylase; D010089:Oxidoreductases, N-Demethylating; D010634:Phenobarbital