TY - JOUR
T1 - Alcohol metabolism and toxicity
T2 - Role of cytochrome P-450
AU - Coon, Minor J.
AU - Koop, Dennis R.
AU - Reeve, Lorraine E.
AU - Crump, Becky L.
N1 - Funding Information:
This research was supported by Grant AA-0622 1 from the National Institute on Alcohol Abuse and Alcoholism. The authors are grateful to Dr. Edward T. Morgan for preliminary experiments on the induction of P-450 isozyme 3a.
PY - 1984/4
Y1 - 1984/4
N2 - Alcohol Metabolism and Toxicity: Role of Cytochrome P-450. Coon, M. J., KOOP, D. R., REEVE, L. E., AND CRUMP, B. L. (1984). Fundam. Appl. Toxicol. 4, 134-143. A new isozyme of cytochrome P-450, designated form 3a on the basis of its relative electrophoretic mobility, has been purified to homogeneity from liver microsomes of rabbits treated chronically with ethanol. This cytochrome has the highest activity of the known rabbit P-450 isozymes in the oxidation of ethanol to acetaldehyde. In view of the reports of others that the hepatotoxicity of acetaminophen is increased in ethanol-treated animals and the human alcoholic, we have determined the activity of the six available P-450 isozymes in the activation of the drug to give an intermediate which forms a conjugate with reduced glutathione. Isozymes 3a, 4, and 6, the three major forms of cytochrome P-450 present in liver microsomes from rabbits chronically treated with ethanol, exhibited the highest activities in the reconstituted enzyme system, whereas isozymes 3b and 3c were 10- to 20-fold less effective and phenobarbital-inducible isozyme 2 was essentially inactive, even in the presence of cytochrome b5. The results obtained thus indicate that induction by ethanol of P-450 isozyme 3a may contribute to the toxicity of acetaminophen but that other cytochromes also play a significant role.
AB - Alcohol Metabolism and Toxicity: Role of Cytochrome P-450. Coon, M. J., KOOP, D. R., REEVE, L. E., AND CRUMP, B. L. (1984). Fundam. Appl. Toxicol. 4, 134-143. A new isozyme of cytochrome P-450, designated form 3a on the basis of its relative electrophoretic mobility, has been purified to homogeneity from liver microsomes of rabbits treated chronically with ethanol. This cytochrome has the highest activity of the known rabbit P-450 isozymes in the oxidation of ethanol to acetaldehyde. In view of the reports of others that the hepatotoxicity of acetaminophen is increased in ethanol-treated animals and the human alcoholic, we have determined the activity of the six available P-450 isozymes in the activation of the drug to give an intermediate which forms a conjugate with reduced glutathione. Isozymes 3a, 4, and 6, the three major forms of cytochrome P-450 present in liver microsomes from rabbits chronically treated with ethanol, exhibited the highest activities in the reconstituted enzyme system, whereas isozymes 3b and 3c were 10- to 20-fold less effective and phenobarbital-inducible isozyme 2 was essentially inactive, even in the presence of cytochrome b5. The results obtained thus indicate that induction by ethanol of P-450 isozyme 3a may contribute to the toxicity of acetaminophen but that other cytochromes also play a significant role.
UR - http://www.scopus.com/inward/record.url?scp=0021167415&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0021167415&partnerID=8YFLogxK
U2 - 10.1093/toxsci/4.2part1.134
DO - 10.1093/toxsci/4.2part1.134
M3 - Article
C2 - 6724188
AN - SCOPUS:0021167415
SN - 1096-6080
VL - 4
SP - 134
EP - 143
JO - Toxicological Sciences
JF - Toxicological Sciences
IS - 2 PART1
ER -