부산대학교 도서관

The [[beta].sub.3]-adrenoreceptor plays a major role in lipolysis but the role and distribution of [[beta].sub.3]-receptors in other specific sites have not been extensively studied. [[beta].sub.3]-adrenergic receptors are present not only in adipose tissue but also in human gall bladder, colon, prostate, and skeletal muscle. Recently, [[beta].sub.3]-adrenergic receptor stimulation was shown to elicit vasorelaxation of rat aorta through the NO-cGMP signal transduction pathway. Here we show that [[beta].sub.3]-receptors are present in human corpus cavernosum and are localized mainly in smooth muscle cells. After activation by a selective [[beta].sub.3]-adrenergic receptor agonist, BRL 37344, there was a cGMP-dependent but NO-independent vasorelaxation that was selectively blocked by a specific [[beta].sub.3]-receptor antagonist. In addition, we report that the human corpus cavernosum exhibits basal [[beta].sub.3]-receptor-mediated vasorelaxant tone and that [[beta].sub.3]-receptor activity is linked to inhibition of the RhoA/ Rho-kinase pathway. These observations indicate that [[beta].sub.3]-receptors may play a physiological role in mediating penile erection and, therefore, could represent a therapeutic target for treatment of erectile dysfunction. erectile dysfunction | Rho kinase | endothelin