Inhibition of Aerobic Respiration of Rat Brain by Desoxycorticosterone in vitro.

Abstract

Because of previous studies indicating an effect of large amts. of steroids on respiration of rat brain cell suspension, concn. -action relationships were studied relating the amt. of steroid to the degree of inhibition produced. Desoxycorticosterone (DC) and its water-soluble glycoside (DCG) were selected for study because these steroids produce more inhibition than other steroids previously investigated. Using standard Warburg technic with 1-hr. control period and 1-hr. after the addition of the steroid, it was found that: (a) Increasing amts. of DC and DCG produce increasing amts. of inhibition. This relationship is reasonably linear, plotting the logarithm of the amt. of DC against % of inhibition produced, (b) With increasing amts. of DC a longer period of time is required to attain maximal inhibition while a comparable effect is more rapidly attained with equimolar amts. of the water-soluble conjugate, DCG. The effect, once attained, remains constant without further increase or release of the inhibition, (c) By this bio-assay the water-solubility of DC at 37.2[degree]C is approx. 3.6 x 10-13 [image].