흰쥐 간 마이크로좀의 cytochrome P - 450 의존성 testosterone hydroxylase 의 활성도 측정 = Assay of cytochrome P - 450 dependent Testosterone Hydroxylases in Liver microsomes of Rats

다국어 초록 (Multilingual Abstract)

A rapid and one time determinable TLC method for the monohydroxytestosterones formed by microsomal cytochrome P-450(P-450) was established, and applying this method the activity of P-450-dependent testosterone hydroxylases was observed in liver microsomes of rats pretreated with phenobarbital(PB). The 14 testosterone metabolites were found on the TLC plate. The amounts of 6-monohydroxytestosterones (2α-, 2β-, 6α-, 6β-,7α-and 16α-OH-T) were determined. The formation of these metabolites showed a good linearity(r = 0.9687-0.9999) corresponding to the concentration of P-450 added up to about 1.0 nmol/min/reaction mixture, and an excellent reproducibility (C.V.= 1.8 ± 1.0%) when determined with 0.5 nmol P-450 in this assay system. The hydroxylation of testosterone to its 2β-OH-T by PB-inducible P-450 was increased (2 fold), while 2α- and 7α-OH-T was rather decreased to 48 and 32%, respectively, compared with those of uninduced one. The 6β-OH-T was predominantly formed by uninducible and PB-inducible P-450, especially PB-inducible P-450 hydroxylated stereospecifically onto the C2-position of testosterone (2α/2β =1: 3.8). However, the oxidation rates of testosterone to its 6α-, 6β- and 16α-OH-T, and the total amount of testosterone metabolites identified were not changed, significantly by the administration of PB.