The authors used incubated adrenal mitochondria to study the in vitro effect of suramin, an antiparasitic drug, on the transformation of corticosterone and 18-hydroxycorticosterone into aldosterone. The results show that, under conditions preserving membrane integrity, the "impermeance" of suramin meant that concentrations similar to the plasma-levels reached in treated patients induced only slight inhibition of the final intramitochondrial steps in aldosterone synthesis. However, ...

The authors incubated adrenal mitochondria to study the in vitro action of cortisol and testosterone on the transformation of corticosterone and 18-hydroxycorticosterone into aldosterone. The results show that cortisol at concentrations of 5 x 10(-6) and 10(-4) M inhibit the conversion of corticosterone into aldosterone by 23.6 to 90%; testosterone 5 x 10(-5) and 10(-4) M inhibit the reaction by 78.4 and 87.2%, respectively. The inhibition of the conversion of 18-hydroxycorticosterone ...

The action of verapamil, a calcium channel blocker, on the last step of aldosterone biosynthesis (transformation of 18-hydroxycorticosterone into aldosterone) was studied using duck adrenal mitochondria in the absence of regulatory factors. Results show that 10(-5) M verapamil inhibits the transformation of 18-hydroxycorticosterone into aldosterone by 52.8%. Moreover, our findings show that verapamil induces only a slight inhibition of respiratory capacity without action on respiratory ...