[Corticosteroid hormone effect on oxygen consumption of rat brain and hippocampus mitochondria and homogenates]

It is shown that addition of desoxycorticosterone to the incubation medium in a concentration of 10(-4) g/ml produces a 65-70% inhibition in the respiration rate of cerebral mitochondria in the medium with piruvate both before addition of ADP (V0) and after this addition (VADP). Corticosteron and hydrocortisone in this concentration affect insignificantly V0 but inhibit noticeably VADP, decrease the respiratory control (RC) and prolong the time of phosphorylation. When using succinate as a substrate the effect of hormones is much less pronounced. The effect of corticosteroids on the studied indices is manifested when adding them to homogenates of cortex and hippocamp as well. Corticosterone added in doses of 10(-5) and 10(-6) g/ml significantly decreases VADP and RC in the hippocamp homogenates and has no effect in these concentrations on the respiration rate of cerebral homogenates, which may evidence for a higher sensitivity of the hippocamp tissue to corticosteroid hormones.