[³H]metyrapol as a tool for studies of interactions of deoxycorticosterone with adrenal cortex mitochondria

Steroid 11β-hydroxylation in beef adrenal cortex mitochondria. Binding affinity and capacity for specific [14C]-labeled steroids and for tritium-labeled metyrapol, an inhibitor of the 11β-hydroxylation reaction

“…It has been shown in a previous paper (Satre et al, 1972) that metyrapol, the reduced derivative of metyrapone, behaves with the same efficiency as metyrapone for binding to adrenal cortex mitochondria and for inhibiting the 11/3hydroxylation of deoxycorticosterone into corticosterone. Because [3H]metyrapol with a high specific radioactivity could be easily prepared, interaction of metyrapol with adrenal cortex mitochondria would be studied by a direct binding technique.…”

“…13, no. as metyrapone on the 11 /3-hydroxylation (Kahnt and Neher, 1971;Satre et al, 1972), and has a higher specific activity. This report describes in detail the binding properties of [3H]metyrapol to adrenal cortex mitochondria and the interactions between [3H]metyrapol and various steroids for binding to the 11 ß-hydroxylation system.…”

“…Materials. [3H]Metyrapol was prepared by reduction of the ketone group of metyrapone with tritiated sodium borohydride, as described in details by Satre et al (1972). The specific radioactivity of the [3H]metyrapol ranged between 0.9 and 1.1 Ci per mmol.…”

[3H]Metyrapol and 4-[131I]Iodometomidate Label Overlapping, but Not Identical, Binding Sites on Rat Adrenal Membranes

“…Subfractionation studies localized the binding site to the inner mitochondrial membrane, known to harbor 11β-hydroxylase. One reason for the early application of this radioligand may have been its easy synthesis (from metyrapone and [ 3 H]NaBH 4 ) …”

“…One reason for the early application of this radioligand may have been its easy synthesis (from metyrapone and [ 3 H]NaBH 4 ). 7 Recently, we have established SARs of several etomidate derivatives at a binding site on rat adrenal membranes with high affinity for the radioligand 4-[ 131 I]iodometomidate 8 ([ 131 I]IMTO). Now, we tested the same and additional compounds at a [ 3 H]metyrapol binding site in the same preparation.…”