![]() |
|
|
1 Department of Medicine, Mount Sinai School of Medicine of the City University of New York, and Section of Liver Disease & Nutrition, Bronx Veterans Administration Hospital, New York
To assess the in vivo role of the microsomal ethanol oxidizing system (MEOS) , an improved assay procedure was developed. When corrected for losses of microsomes during the preparation, the activity of MEOS in vitro corresponded to 20 to 25% of the in vivo rate of ethanol metabolism in the rat and could account for most of the residual ethanol metabolism after inhibition of alcohol dehydrogenase by pyrazole. Under these conditions, the apparent Km of MEOS in vitro coincided with the apparent Km of the blood ethanol disappearance in vivo. Furthermore, administration of ethanol to rats for 24 days increased blood ethanol clearance, with a parallel rise in MEOS activity, whereas the activities of alcohol dehydrogenase and catalase remained unchanged or decreased. Moreover, barbiturate treatment for four to five days also increased total MEOS activity in the liver and this was accompanied by a moderate acceleration of blood ethanol clearance. The latter effect was masked however if significant amounts of barbiturates were still present in the blood when ethanol was given. In addition. administration of one dose of barbiturate slowed blood ethanol clearance and abolished its increase induced by ethanol pretreatment, suggesting that barbiturates interfere with the metabolism of ethanol. In view of the parallel increase of blood ethanol clearance in vivo and MEOS activity in vitro after ethanol or barbiturate pretreatment, it is proposed that MEOS plays a significant role in vivo, a conclusion supported by the correspondence of the kinetic data of MEOS in vitro and of blood ethanol clearance after alcohol dehydrogenase inhibition in vivo.
Submitted on November 29, 1971
This article has been cited by other articles:
![]() |
P. J. Murphy The Development of Drug Metabolism Research as Expressed in the Publications of ASPET: Part 2, 1959-1983 Drug Metab. Dispos., June 1, 2008; 36(6): 981 - 985. [Abstract] [Full Text] [PDF] |
||||
![]() |
Y. Lu, X. Wang, and A. I. Cederbaum Lipopolysaccharide-induced liver injury in rats treated with the CYP2E1 inducer pyrazole Am J Physiol Gastrointest Liver Physiol, August 1, 2005; 289(2): G308 - G319. [Abstract] [Full Text] [PDF] |
||||
![]() |
I D Norton, M V Apte, P S Haber, G W McCaughan, R C Pirola, and J S Wilson Cytochrome P4502E1 is present in rat pancreas and is induced by chronic ethanol administration Gut, March 1, 1998; 42(3): 426 - 430. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. DiPadova, R. Roine, M. Frezza, R. T. Gentry, E. Baraona, and C. S. Lieber Effects of Ranitidine on Blood Alcohol Levels After Ethanol Ingestion: Comparison With Other H2-Receptor Antagonists JAMA, January 1, 1992; 267(1): 83 - 86. [Abstract] [PDF] |
||||
![]() |
S. O'Neill, K. F. Tipton, J. S. Prichard, and A. Quinlan Survival After High Blood Alcohol Levels: Association With First-Order Elimination Kinetics Arch Intern Med, March 1, 1984; 144(3): 641 - 642. [Abstract] [PDF] |
||||
![]() |
M. J. Eckardt, T. C. Harford, C. T. Kaelber, E. S. Parker, L. S. Rosenthal, R. S. Ryback, G. C. Salmoiraghi, E. Vanderveen, and K. R. Warren Health Hazards Associated With Alcohol Consumption JAMA, August 7, 1981; 246(6): 648 - 666. [Abstract] [PDF] |
||||