title: Selective 19-hydroxylase inhibition by an aromatase inhibitor, 4-hydroxyandrostenedione.
abstract: 19-Nor-deoxycorticosterone is a newly recognized mineralocorticoid which has been associated with some forms of genetic, experimental, and human hypertension. To further examine this relationship, specific inhibitors of 19-nor-deoxycorticosterone biosynthesis must be developed. Since 19-hydroxylation is the pivotal step in both 19-nor-deoxycorticosterone biosynthesis and aromatization of androgens to estrogens, we evaluated an aromatase inhibitor, 4-hydroxyandrost-4-ene-3,17-dione on the inhibition of 19-hydroxylation in both rat and human adrenal mitochondria in vitro and 19-nor-deoxycorticosterone production and blood pressure in spontaneously hypertensive rats in vivo. Adrenal mitochondria from 48 male Sprague-Dawley rats and 1 patient with an aldosterone-producing adenoma were incubated in the presence of deoxycorticosterone substrate both with and without 4-hydroxyandrost-4-ene-3,17-dione. 4-Hydroxyandrost-4-ene-3,17-dione produced significant inhibition of 19-hydroxy-deoxycorticosterone production in both rat and human adrenal mitochondria, with a smaller and not significant inhibition of corticosterone and 18-hydroxy-corticosterone. 4-Hydroxyandrost-4-ene-3,17-dione given subcutaneously to spontaneously hypertensive rats lowered 19-nor-deoxycorticosterone by 69% and completely abolished hypertension compared to Wistar-Kyoto controls. These data demonstrate that 4-hydroxyandrost-4-ene-3,17-dione is a specific inhibitor of 19-hydroxylase, that it lowers 19-nor-deoxycorticosterone production and prevents hypertension in the spontaneously hypertensive rat. These studies reinforce the possible pathogenic significance of 19-nor-deoxycorticosterone in hypertension in spontaneously hypertensive rats.
authors.affiliation: Evans Memorial Department of Clinical Research, University Hospital, Boston University Medical Center, Mass.
authors.forename: G T
authors.initials: GT
authors.lastname: Griffing
authors.forename: M
authors.initials: M
authors.lastname: Holbrook
authors.forename: J C
authors.initials: JC
authors.lastname: Melby
authors.forename: A H
authors.initials: AH
authors.lastname: Brodie
mesh_terms: D000735:Androstenedione / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D003900:Desoxycorticosterone / Q000031:analogs & derivatives* / Q000096:biosynthesis; D006801:Humans; D006973:Hypertension / Q000209:etiology*; D008297:Male; D051381:Rats; D011918:Rats, Inbred SHR; D011919:Rats, Inbred Strains; D011921:Rats, Inbred WKY
chemical_list: D000735:Androstenedione; D003900:Desoxycorticosterone; C019026:19-nordeoxycorticosterone; C014594:formestane