title: Determination of age-related changes of cytochrome P-450 sensitive to mepyramine in rat hepatic microsomes.
abstract: The cytochrome P-450 (Cyt P-450) sensitive to mepyramine (HP-450) in liver microsome is a protein that possesses properties of both H1 receptor and cytochrome P-450. We used [3H]mepyramine radioligand binding assay and enzymological technique to study the kinetic properties of HP-450 and Cyt P-450. Age-related changes in the Bmax, Kd of HP-450 and Cyt P-450 in rat hepatic microsome were demonstrated. The levels of Bmax for both HP-450 and the Cyt P-450 dramatically increased in the postnatal period from the second to the eighth week, and reached maximum steady status during the eighth to tenth week. The values of Bmax of HP-450 correlated well with the content of Cyt P-450 in rat liver microsome (r = 0.625). The affinity of HP-450 (Kd) decreased with the growth of rats during postnatal. No sexual-related difference was observed in this experiment.
authors.affiliation: Department of Pharmacology, Guangxi Medical University, Nanning.
authors.forename: N P
authors.initials: NP
authors.lastname: Wang
authors.forename: L Q
authors.initials: LQ
authors.lastname: Zang
authors.forename: R B
authors.initials: RB
authors.lastname: Huang
authors.forename: Z Q
authors.initials: ZQ
authors.lastname: Meng
mesh_terms: D000375:Aging / Q000378:metabolism*; D000818:Animals; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D005260:Female; D006634:Histamine H1 Antagonists; D007527:Isoenzymes / Q000378:metabolism*; D008297:Male; D008862:Microsomes, Liver / Q000201:enzymology*; D011738:Pyrilamine / Q000037:antagonists & inhibitors; D051381:Rats; D017208:Rats, Wistar
chemical_list: D006634:Histamine H1 Antagonists; D007527:Isoenzymes; D003577:Cytochrome P-450 Enzyme System; D011738:Pyrilamine