Complex formation by 3 H-aldosterone in rat kidney and liver

Low molecular weight polar complexes were shown to be formed $\text{in vivo}$ from ³H-aldosterone in both kidney and liver subcellular fractions, the majority being present in the cytosol fractions. Significant differences were observed between the quantities of polar complexes present in kidney subcellular fractions from intact and adrenalectomized male rats and also between the quantities of these kidney polar complexes from spironolactone treated male rats. ³H-aldosterone macro-molecule complexes were shown to exist in appreciable quantities only in the kidney cytosol fractions of adrenalectomized male rats. These gel filtration studies also showed the ³H-aldosterone labeled macromolecule complexes to consist of two protein peaks; one of high molecular weight and the other of lower molecular weight (～50,000 mol. wt.). The amount of ³H-aldosterone labeled protein complexes in kidney cytosol was greatly reduced when adrenalectomized rats were pretreated $\text{in vivo}$ with spironolactone.