PT  - JOURNAL ARTICLE
AU  - H D Colby
AU  - P B Johnson
AU  - J S Zulkoski
AU  - M R Pope
TI  - Differential effects of adrenocorticotropic hormone on adrenal microsomal xenobiotic and steroid metabolism in guinea pigs.
DP  - 1982 Jul 01
TA  - Drug Metabolism and Disposition
PG  - 326--329
VI  - 10
IP  - 4
4099  - http://dmd.aspetjournals.org/content/10/4/326.short
4100  - http://dmd.aspetjournals.org/content/10/4/326.full
SO  - Drug Metab Dispos1982 Jul 01; 10
AB  - The effects of adrenocorticotropic hormone (ACTH) administration to guinea pigs on the activities of adrenal microsomal monooxygenases were studied. ACTH treatment decreased the rates of adrenal benzphetamine (BZ) demethylation and benzo[a]pyrene (BP) hydroxylation but had no effect on the same reactions in hepatic microsomes. Adrenal microsomal steroid hydroxylation reactions were unaffected (21-hydroxylation) or stimulated (17 alpha-hydroxylation) by ACTH. Although ACTH treatment decreased adrenal BP hydroxylase activity, the relative quantity of the various BP metabolites, as determined by HPLC, did not change. Adrenal microsomal cytochrome P-450 concentrations were decreased by ACTH but proportionately less than the decreases in adrenal xenobiotic metabolism. The maximal type I spectral changes produced by xenobiotics in adrenal microsomes were decreased in size by ACTH treatment, but steroid-induced difference spectra were unaffected. The results indicate that ACTH selectively decreases the rates of adrenal xenobiotic metabolism, perhaps by producing a selective decline in the concentration(s) of those cytochromes P-450 involved in the metabolism of foreign compounds.