| Abstract: | Abstract. Proximal and distal tubular segments of the subcapsular nephron and segments of the ascending limb of Henle's loop were dissected out freehand from lyophilized kidney section of male rats after bilateral adrenalectomy. The microdissected nephron structures were weighed with a quartz fibre balance. Na K ATPase was determined by analyzing the total ATPase and the Mg ATPase in dissected material. As soon as 6 h after adrenal enucleation a 65% reduction of Na K ATPase activity in the ascending limb of Henle's loop and a 81 % diminution in the distal convoluted portion were detected; 24 h after adrenalectomy an additional reduction of the transport enzyme in the proximal convoluted portion was simulated by an enzyme activity increase in the sham-operated controls. In contrast to previous authors working with homogenate or membrane fraction of the whole kidney, the present quantitative histochemical results indicate a close adaptation of Na K ATPase to the altered sodium transport in rat kidney after adrenalectomy. |
