scholarly journals Stimulation of Hepatic Microsomal Drug-Metabolizing Enzyme Systems in Primates by DDT

1966 ◽  
Vol 51 (2) ◽  
pp. 213-218 ◽  
Author(s):  
Mont R. Juchau ◽  
Theodore E. Gram ◽  
James R. Fouts
Keyword(s):  
Enzyme Systems ◽  
Drug Metabolizing Enzyme ◽  
Metabolizing Enzyme ◽  
Stimulation Of

scholarly journals Hepatic drug-metabolizing enzyme activity in rats pretreated with (−)-emetine or (±)-2,3-dehydroemetine

1970 ◽  
Vol 117 (3) ◽  
pp. 491-498 ◽  
Author(s):  
H. H. Miller ◽  
R. K. Johnson ◽  
J. D. Donahue ◽  
W. R. Jondorf
Keyword(s):  
Enzyme Activity ◽  
Female Rats ◽  
Inhibitory Effects ◽  
Hepatic Drug ◽  
Azo Reduction ◽  
Drug Metabolizing Enzyme ◽  
Metabolizing Enzyme ◽  
Sodium Phenobarbital ◽  
Stimulation Of

1. Pretreatment of female rats with (−)-emetine or (±)-2,3-dehydroemetine (at 18μmol/kg body wt. for 24h) prolongs the hexobarbital-induced sleeping-time of the treated animals. 2. This effect is not observed on pretreating animals with other compounds closely related to (−)-emetine, such as (−)-isoemetine or (+)-O-methylpsychotrine. 3. Liver microsomal drug-metabolizing enzyme activity in vitro as measured by N-demethylation of aminopyrine and azo-reduction of Neoprontosil is inhibited in rats pretreated with (−)-emetine or with (±)-2,3-dehydroemetine. 4. These inhibitory effects on drug metabolism in vitro are not observed in corresponding experiments involving pretreatment of rats with (−)-isoemetine or (+)-O-methylpsychotrine. 5. Co-administration of emetine or 2,3-dehydroemetine and sodium phenobarbital or 1,1-dichloro-2-o-chlorophenyl-2-p-chlorophenylethane to rats abolishes or greatly diminishes the stimulation of drug-metabolizing enzyme activity in vitro usually obtained by the administration of phenobarbital or 1,1-dichloro-2-o-chlorophenyl-2-p-chlorophenylethane alone. 6. Further, in rats pretreated with sodium phenobarbital and subsequently injected with emetine or 2,3-dehydroemetine the pre-stimulated drug-metabolizing enzyme activity in vitro is diminished. 7. The inhibitory effects on drug-metabolizing enzyme activity after pretreatment with (−)-emetine or (±)-2,3-dehydroemetine do not appear to be related to NADPH generation.

scholarly journals ENZYME-MEMBRANE RELATIONSHIP IN PHENOBARBITAL INDUCTION OF SYNTHESIS OF DRUG-METABOLIZING ENZYME SYSTEM AND PROLIFERATION OF ENDOPLASMIC MEMBRANES

1966 ◽  
Vol 28 (2) ◽  
pp. 181-198 ◽  
Author(s):  
Sten Orrenius ◽  
Jan L. E. Ericsson
Keyword(s):  
Actinomycin D ◽  
Enzyme System ◽  
Drug Metabolizing Enzyme ◽  
Induction Process ◽  
Autophagic Activity ◽  
Metabolizing Enzyme ◽  
Parenchymal Cells ◽  
Phenobarbital Induction ◽  
Stimulation Of

The enzyme-membrane relationship in phenobarbital induction of synthesis of drug-metabolizing enzyme system and proliferation of endoplasmic membranes has been further studied. Ultrastructural observations suggest that newly formed endoplasmic membranes in rat liver parenchymal cells arise through continuous outgrowth and budding off from pre-existing cisternae and tubules of rough-surfaced endoplasmic reticulum. The membranes induced by phenobarbital treatment persist in the cytoplasm of the hepatocyte for up to 15 days after the last of a series of 5 phenobarbital injections; the phase of regression of the induced enzymes lasts for only 5 days. Disappearance of the membranes is gradual and does not seem to be associated with increased autophagic activity in the cell. A second series of injections of phenobarbital to previously induced rats—exhibiting normal drug-hydroxylating activity but an excess of liver endoplasmic membranes—is associated with a stimulation of the rate of Pi32 incorporation into microsomal phospholipid in vivo, similar to that found during the original induction process. Administration of Actinomycin D following a single phenobarbital injection delays the regression of the enhanced drug-hydroxylating activity. Finally, the effects of Actinomycin D and puromycin on the stimulated membrane formation are discussed.

scholarly journals Sex Difference in the Effects of Δ9-Tetrahydrocannabinol and Cannabidiol on Pentobarbital-Induced Sleeping Time and Hepatic Microsomal Drug Metabolizing Enzyme Systems in Mice

1983 ◽  
Vol 103 (12) ◽  
pp. 1289-1297 ◽  
Author(s):  
KOICHI HAMAJIMA ◽  
KAZUHITO WATANABE ◽  
SHIZUO NARIMATSU ◽  
YUJI TATEOKA ◽  
IKUO YAMAMOTO ◽  
...  
Keyword(s):  
Sex Difference ◽  
Sleeping Time ◽  
Enzyme Systems ◽  
Drug Metabolizing Enzyme ◽  
Metabolizing Enzyme

Drug metabolizing enzyme systems in the houbara bustard (Chlamydotis undulata)

1998 ◽  
Vol 120 (3) ◽  
pp. 365-372 ◽  
Author(s):  
Tom A. Bailey ◽  
Annie John ◽  
Eric P. Mensah-Brown ◽  
Andrew Garner ◽  
Jaime Samour ◽  
...  
Keyword(s):  
Enzyme Systems ◽  
Drug Metabolizing Enzyme ◽  
Houbara Bustard ◽  
Metabolizing Enzyme

scholarly journals The effects of benzopyrene and safrole on biphenyl 2-hydroxylase and other drug-metabolizing enzymes

1976 ◽  
Vol 154 (3) ◽  
pp. 773-780 ◽  
Author(s):  
F J. McPherson ◽  
J W. Bridges ◽  
D V. Parke
Keyword(s):  
Intraperitoneal Administration ◽  
Albino Rats ◽  
Hydroxylase Activity ◽  
Metabolizing Enzymes ◽  
Enzyme Systems ◽  
Drug Metabolizing Enzyme ◽  
In Vitro Investigation ◽  
Wistar Albino Rats ◽  
Metabolizing Enzyme

A study was made of the nature and specificity of the increase in biphenyl 2-hydroxylase activity after preincubation of liver microsomal preparations with various carcinogens in vitro. This enhancement of enzyme activity in vitro was investigated in mouse, hamster and rat, and although the rat appears to be atypical in the variation of the pattern of 2- and 4-hydroxylation with age, similar enhancements were detectable in each species examined. An increase in biphenyl 2-hydroxylase activity was apparent 2h after intraperitoneal administration of safrole or benzopyrene to mature Wistar albino rats and appeared to be similar in nature to that observed after preincubation of liver microsomal preparations with the same chemical in vitro. Investigation of other drug-metabolizing enzyme systems suggests that the enhancing effects of carcinogens in vitro are specific for biphenyl 2-hydroxylase. No correlation between the enhancement of biphenyl 2-hydroxylase and inhibtion of biphenyl 4-hydroxylase was apparent.

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