Relaxation of isolated corpus cavernosum induced by smooth-muscle relaxant drugs. A comparative study.

Intracavernous injection of vasoactive substances are used in the treatment and investigation of impotence. We studied the effects induced by some pharmacological agents on strips of human erectile tissue. Specimens of corpus cavernosum were obtained from 16 men undergoing cystectomy or penectomy for bladder or penile malignancy. Strip preparations were mounted in thermostically controlled baths containing Krebs solution. Pharmacologic effects were monitored by means of an isotonic transducer. Papaverine was shown to be the substance able to cause the biggest relaxation effect. The authors compared the action of other drugs having a relaxant effect, studied the antagonist effects of epinephrine and dopamine on the pharmacologically relaxed preparations, and stressed that the relaxation of the erectile tissue has a determinant role in the appearance and maintenance of erection.