Quantitative analysis of adrenergic alpha-1 and alpha-2 receptors in human prostatic urethral tissue.

We measured the adrenergic alpha-1 and alpha-2 receptors in 3 types of prostatic tissue (prostatic urethral mucosa, prostatic adenoma and prostatic capsule) in a group of patients with benign prostatic hypertrophy (BPH) and in another group without BPH, using radioligand binding techniques. In all tissues examined, more alpha-1 and alpha-2 receptors were found in the hypertrophy group than in the other group. The increase in density of these receptors in the hypertrophy group was most marked in the prostatic adenoma. The density of alpha-1 and alpha-2 receptors was almost the same in the adenoma in both groups. The prostatic capsule and urethra in both groups contained more alpha-1 than alpha-2 receptors. Both receptors were found more in the adenoma than in the other 2 tissues in both groups. These results suggest that alpha-1 and alpha-2 receptors both play an important part in the symptoms of benign prostatic hypertrophy.