Open AccessPotentiation of EPN-induced Inhibition of Liver Microsomal Carboxylesterase by Addition of Liver Cytosol from 6-Aminonicotinam de-Treated, Starved Rats
Author(s) -
S Sugiyama,
Takaya Satoh,
Koichi Ueno,
Takashi Isobe,
Haruo Kitagawa
Publication year - 1984
Publication title -
japanese journal of pharmacology/japanese journal of pharmacology
Language(s) - English
Resource type - Journals
eISSN - 1347-3506
pISSN - 0021-5198
DOI - 10.1254/jjp.35.433
Subject(s) - carboxylesterase , cytosol , long term potentiation , microsome , nicotinamide , chemistry , cytochrome , biochemistry , endocrinology , medicine , enzyme , pharmacology , biology , receptor
Addition of liver cytosol from 16 hr-starved rats treated with 6-aminonicotinamide to rat liver microsomes caused potentiation of the anti-carboxylesterase action of ethyl-p-nitrophenyl phenylphosphonothioate (EPN). This was not found when liver cytosol from non-pretreated rats after 16 hr-starvation was used. This potentiation of EPN-induced inhibition of carboxylesterase may be, at least in part, explained by the fact that treatment of rats with 6-aminonicotinamide resulted in a significant increase in NADPH level in liver cytosol which, in turn, stimulated formation of an EPN oxygen analog, a potent inhibitor of carboxylesterase, through cytochrome P-450-coupled monooxygenase.