1. Involvement of beta 3-adrenergic receptor activation via cyclic GMP- but not NO-dependent mechanisms in human corpus cavernosum function.
- Author
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Cirino G, Sorrentino R, di Villa Bianca Rd, Popolo A, Palmieri A, Imbimbo C, Fusco F, Longo N, Tajana G, Ignarro LJ, and Mirone V
- Subjects
- Blotting, Western, Humans, Immunohistochemistry, In Vitro Techniques, Male, Cyclic GMP physiology, Nitric Oxide physiology, Penis physiology, Receptors, Adrenergic, beta-3 metabolism
- Abstract
The beta(3)-adrenoreceptor plays a major role in lipolysis but the role and distribution of beta(3)-receptors in other specific sites have not been extensively studied. beta(3)-adrenergic receptors are present not only in adipose tissue but also in human gall bladder, colon, prostate, and skeletal muscle. Recently, beta(3)-adrenergic receptor stimulation was shown to elicit vasorelaxation of rat aorta through the NO-cGMP signal transduction pathway. Here we show that beta(3)-receptors are present in human corpus cavernosum and are localized mainly in smooth muscle cells. After activation by a selective beta(3)-adrenergic receptor agonist, BRL 37344, there was a cGMP-dependent but NO-independent vasorelaxation that was selectively blocked by a specific beta(3)-receptor antagonist. In addition, we report that the human corpus cavernosum exhibits basal beta(3)-receptor-mediated vasorelaxant tone and that beta(3)-receptor activity is linked to inhibition of the RhoA/Rho-kinase pathway. These observations indicate that beta(3)-receptors may play a physiological role in mediating penile erection and, therefore, could represent a therapeutic target for treatment of erectile dysfunction.
- Published
- 2003
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