Adenosine actions are preserved in corpus cavernosum from obese and type II diabetic db/db mouse.

Carneiro, Fernando Silva; Giachini, Fernanda Regina Casagrande; Lima, Victor Vitorino; Neotzold, Zidonia Nunes; Leite, Romulo; Inscho, Edward W.; Passaglia, Rita de Cassia Aleixo Tostes; Webb, Robert Clinton

Adenosine actions are preserved in corpus cavernosum from obese and type II diabetic db/db mouse.

Date

2008

Authors

Carneiro, Fernando Silva

Giachini, Fernanda Regina Casagrande

Lima, Victor Vitorino

Neotzold, Zidonia Nunes

Leite, Romulo

Inscho, Edward W.

Passaglia, Rita de Cassia Aleixo Tostes

Webb, Robert Clinton

Abstract

Introduction—Erectile dysfunction (ED) in diabetes is associated with autonomic neuropathy and endothelial dysfunction. Whereas the nonadrenergic-noncholinergic (NANC)/neurogenic nitric oxide pathway has received great attention in diabetes-associated ED, few studies have addressed sympathetic overactivity. Aim—To test the hypothesis that adenosine-induced inhibition of adrenergic-mediated contractile responses in mouse corpus cavernosum is impaired in the presence of diabetes. Methods—The db/db (obesity and type II diabetes caused by a leptin receptor mutation) mouse strain was used as a model of obesity and type II diabetes, and standard procedures were performed to evaluate functional cavernosal responses. Main Outcome Measures—Increased cavernosal responses to sympathetic stimulation in db/ db mice are not associated with impaired prejunctional actions of adenosine. Results—Electrical field stimulation (EFS)-, but not phenylephrine (PE)-, induced contractions are enhanced in cavernosal strips from db/db mice in comparison with those from lean littermates. Direct effects of adenosine, 2-chloro-adenosine, A1 receptor agonist C-8031 (N6 cyclopentyladenosine), and sodium nitroprusside are similar between the strips from lean and db/ db mice, whereas relaxant responses to acetylcholine and NANC stimulation are significantly impaired in the cavernosal strips from db/db mice. 5′-Iodotubercidin (adenosine kinase inhibitor) and dipyridamole (inhibitor of adenosine transport), as well as the A1 agonist C-8031, significantly and similarly inhibit contractions induced by stimulation of adrenergic nerves in the cavernosal strips from lean and db/db mice. Conclusions—Results from this study suggest that corpora cavernosa from obese and diabetic db/db mice display altered neural-mediated responses that would favor penile detumescence, i.e., increased contractile response to adrenergic nerve stimulation and decreased relaxant responses upon activation of NANC nerves. However, increased cavernosal responses to adrenergic nerve stimulation are not due to impaired negative modulation of sympathetic neurotransmission by adenosine in this diabetic model.

Keywords

Obesity, Diabetes, Sympathetic Neurotransmission, Animal Models

Citation

CARNEIRO, F. S. et al. Adenosine actions are preserved in corpus cavernosum from obese and type II diabetic db/db mouse. The Journal of Sexual Medicine, v. 5, p. 1156-1166, 2008. Disponível em: <http://www.sciencedirect.com/science/article/pii/S1743609515320385>. Acesso em: 10 jan. 2017.