Chick microsomal oxidases. Isolation, properties, and stimulation by embryonic exposure to 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane

Abstract

The optimum conditions for the activity of the chick liver microsomal oxidative , -dimethylaniline demethylase have been established. Reduced nicotinamide-adenine dinucleotide phosphate was required and was partially replaced by reduced nicotinamide-adenine dinucleotide. The enzyme was competitively inhibited by /3-diethylaminoethyl diphenylpropylacetate. Michaelis constants in the absence and in the presence of /3-diethylaminoethyl diphenylpropylacetate were determined for , -dimethylaniline and , -dimethylaniline A-oxide. The data presented in this work demonstrate that the rate of , -dimethylaniline A-oxide demethylation by chick liver microsomal fraction is sufficiently high for the A-oxide to be considered as an intermediate in the oxidative demethylation of , -dimethylaniline. Ferrous ions activated the microsomal demethylase when incubated with nicotinamide-adenine dinucleotide phosphate and gave a greater oxidative reaction in the absence of nicotinumerous studies have been conducted on the oxidative demethylation of A-methyl compounds. In the presence of NADPH and oxygen the microsomal fraction catalyzed the oxidation of some of the A-

Effects of different classes of pesticides on pentobarbital anesthesia and toxicity in Japanese quail

“…Although Stephen and coworkers (1971) found an increase in sleeping time in chickens, they were unable to show any consistent change in liver microsomal enzyme activity. Contrary to finding a decrease in liver microsomal activity, Abou-Donia and Menzel (1968) found that liver microsomal oxidative activity was increased in chicks hatched from eggs which had been injected with DDT. Peakall (1967, 1970 observed an increase in the rate of steroid metabolism by hepatic microsomes of pigeons or doves treated with DDT, also suggesting a stimulation of liver microsomal activity.…”

Characterization of covalent binding of [14C]‐2‐chloro‐4‐acetotoluidide to microsomes of starling liver and kidney

“…Phenobarbital, which has already been shown to induce the hepatic of starlings and chickens (15,26), increased covalent binding to microsomal proteins in vitro. SKF 525-A, which has been shown to be an inhibitor of avian hepatic p450 (27,28), also inhibited binding of [14C]-CAT to starling hepatic microsomes in the present study. Binding was also inhibited by deletions of cofactors that are necessary for the activity of the hepatic P450, for example, NADP and 0,.…”

Sucralose, A Synthetic Organochlorine Sweetener: Overview Of Biological Issues

“…Pesticides such as chlorpyrifos, tetrachlorohydroquinone, chlordecone, heptachlor, chlorthiophos, dicapthon, fluvalinate, and permethrin interact with P-gp (Lanning et al, 1996; Bain and LeBlanc, 1996). Organochlorine insecticides and pesticides that are metabolized by CYP isozymes include chlorpyrifos (Tang et al, 2001), p,p ‘-DDT [1,1,1-trichloro-2,2- bis ( p -chlorophenyl)ethane] (Abou-Donia and Menzel, 1968a; 1968b; Kitamura et al, 2002), and methoxychlor (Hu and Kupfer, 2002). The herbicides acetochlor, butachlor, and metolachlor are metabolized by CYP (Coleman et al, 2000), as are many industrial OC compounds (Gonzalez and Gelboin, 1994) including chlorinated benzenes (Bogaards et al, 1995), chloroform (Gemma et al, 2003), chlorofluorocarbons (Dekant et al, 1995), and trichloroethylene (Lipscomb et al, 1997).…”