Demonstration of a specific cytosol receptor in the normal and hyperplastic canine prostate for...

A specific receptor protein has been demonstrated for 5alpha-androstane-3alpha, 17alpha-diol in cytoplasmic extracts of normal and hyperplastic canine prostates. The receptor molecule, with a sedimentation coefficient of 4-5S, has been identified by the use of sucrose gradient centrifugation of tissue fractions which had been labelled in vitro with tritiated 5alpha-androstane-3alpha, 17alpha-diol. The receptor showed a relatively high affinity for this compound whereas binding could not be demonstrated with other labelled C19 steroids. In addition binding of tritiated 5alpha-androstane-3alpha, 17alpha-diol was not affected by the presence of 50-fold excesses of other C19 steroids.