Sex and strain differences in mouse hepatic microsomal coumarin 7-hydroxylase activity

• Published in: Food and chemical toxicology Vol. 32; no. 4; pp. 387 - 390
• Main Authors: van Iersel, M., Walters, D.G., Price, R.J., Lovell, D.P., Lake, B.G.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.04.1994; New York, NY Elsevier Science
• Subjects: Animals; Aryl Hydrocarbon Hydroxylases; Biological and medical sciences; Cytochrome P-450 CYP2A6; Cytochrome P-450 Enzyme System - metabolism; Cytochrome P450 Family 2; Female; Leerstoelgroep Toxicologie; Male; Medical sciences; Mice; Mice, Inbred A; Mice, Inbred AKR; Mice, Inbred BALB C; Mice, Inbred C3H; Mice, Inbred C57BL; Mice, Inbred CBA; Mice, Inbred DBA; Microsomes, Liver - enzymology; Mixed Function Oxygenases - metabolism; Plant poisons toxicology; Sex Characteristics; Species Specificity; Sub-department of Toxicology; Toxicologie; Toxicology; Hydroxylation; Enzyme; Coumarine derivatives; Liver; Hydroxylase; Rodentia; Sex; Strain specificity; Microsome; In vitro; Vertebrata; Mammalia; Intraindividual comparison; Mouse; Animal; Plant origin; Essential oil
• ISSN: 0278-6915; 1873-6351
• DOI: 10.1016/0278-6915(94)90078-7

Hepatic microsomal coumarin 7-hydroxylase activity has been determined in male and female mice of strains A/J, AKR, BALB/c, CBA/Ca, C3H/He, C57BL/6J, DBA/2 and 129. In males, coumarin 7-hydroxylase activity was highest in liver microsomes from DBA/2 mice and lowest in BALB/c mice. With female mice enzyme activity was highest in DBA/2 and 129 strains, intermediate in the CBA/Ca strain and comparatively low in the other five strains. Marked sex differences were observed in coumarin 7-hydroxylase activity with enzyme activity in female animals from strains DBA/2, 129 and CBA/Ca being 4.8-, 6.2- and 4.8-fold higher, respectively, than in male mice. In contrast, only minor sex and strain differences in levels of total microsomal cytochrome P-450 were observed. These results demonstrate marked sex and strain differences in mouse hepatic microsomal coumarin 7-hydroxylase activity. Such differences may be due to variations in particular cytochrome P-450 isoenzymes such as CYP2A5, not all of which can be explained by the known allelic difference in the Cyp2a-5 locus.