Sympathetic Hyperactivity, Increased Tyrosine Hydroxylase and Exaggerated Corpus Cavernosum Relaxations Associated with Oxidative Stress Plays a Major Role in the Penis Dysfunction in Townes Sickle Cell Mouse

Autor(es)

Silva, Fabio H. ; Claudino, Mario A. ; Calmasini, Fabiano B. ; Alexandre, Eduardo C. ; Franco-Penteado, Carla ; Burnett, Arthur L. ; Antunes, Edson ; Costa, Fernando F.

• Tipo de documento: Artigo Científico
• Fonte: PLoS One; v. 11, n. 12 DEC 9 2016.
• Citações Web of Science: 2

Resumo

Background Sickle cell disease patients display priapism that may progress to erectile dysfunction. However, little is known about the pathophysiological alterations of corpus cavernosum in sickle cell disease. Objective Thus, this study aimed to evaluate the functional and molecular alterations of sympathetic machinery and nitric oxide-cyclic guanosine monophosphate signaling pathway in Townes transgenic sickle cell disease mice. Methods Concentration-response curves to contractile (phenylephrine) and relaxant agents (acetylcholine and sodium nitroprusside) were obtained in corpus cavernosum strips from sickle and C57BL/6 (control) mice. Neurogenic contractions and nitrergic relaxations were obtained using electrical-field stimulation. Measurements of endothelial nitric oxide synthase (eNOS), neuronal nitric oxide synthase (nNOS), phosphodiesterase-5 (PDE5) and a alpha(1A)-, alpha(1B)-and alpha(1D)-adrenoceptor mRNA expressions and reactive-oxygen species were performed. Tyrosine hydroxylase phosphorylated at Ser-31 and total tyrosine hydroxylase protein expressions in cavernosal tissues were also measured. Results The neurogenic contractions were higher in the sickle cell disease group, in association with elevated tyrosine hydroxylase phosphorylated at Ser-31 and total tyrosine hydroxylase protein expression, as well as increased tyrosine hydroxylase mRNA expression. Likewise, phenylephrine-induced contractions were greater in the sickle mice, whereas a alpha(1A)-, alpha(1B)-and alpha(1D)-adrenoceptor mRNA expression remained unchanged. Cavernosal relaxations to acetylcholine, sodium nitroprusside and EFS were higher in sickle mice, accompanied by decreased eNOS and nNOS, along with lower PDE5 mRNA expression. An increase of about 40% in reactive-oxygen species generation in corpus cavernosum from sickle mice was also detected. Conclusion Our study shows that decreased nitric oxide bioavailability in erectile tissue due to increased oxidative stress leads to both sympathetic hyperactivity and dysregulation of nitric oxide signaling in corpus cavernosum from Townes sickle mice. (AU)

• Processo FAPESP: 14/00984-3 - Doenças dos glóbulos vermelhos: fisiopatologia e novas abordagens terapêuticas
• Beneficiário: Fernando Ferreira Costa
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 13/19781-2 - Terapêutica de prevenção do priapismo em camundongos transgênicos para anemia falciforme com drogas que interferem na via de sinalização NO/GCs/GMPc.
• Beneficiário: Fábio Henrique da Silva
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado