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Increased contractile responses in corpora cavernosa of heart failure rats
Author(s) -
Carneiro Fernando S,
Biancardi Vinicia C,
Carneiro Zidonia N,
Stern Javier E,
Webb R Clinton,
Tostes Rita C
Publication year - 2010
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.24.1_supplement.lb576
Subject(s) - medicine , endocrinology , contractility , phenylephrine , heart failure , sodium nitroprusside , nitric oxide , blood pressure
Heart failure (HF) is a risk factor for erectile dysfunction (ED). HF patients experience a decreased libido, frequency of coitus and sexual performance. The mechanisms underlying the association of HF and ED are unknown. We hypothesize that HF increases cavernosal reactivity. Methods and Results HF was induced, in Wistar male rats (8 week‐old), by left coronary artery ligation for 6 weeks. Ejection fraction (Sham: 85.5±3.3 vs HF: 33.9±3.0, %) and fractional shortening (Sham: 63.9±3.8 vs HF: 17.3±1.7, %) were measured to confirm the presence of HF. HF rats displayed increased cavernosal contractile responses to KCl (Sham: 0.55±0.07 vs HF: 0.82±0.06, mN/mg) and phenylephrine in the absence (Sham: 0.71±0.05 vs HF: 0.97±0.05, mN/mg) or in the presence of L‐NAME (Sham: 0.70±0.05 vs HF: 1.14±0.06, mN/mg). Sympathetic‐mediated contractile responses were increased in cavernosal strips of HF rats in the absence (Sham: 0.55±0.09 vs HF: 1.03±0.08, mN/mg) and in the presence of L‐NAME (Sham: 0.67±0.1 vs HF: 1.33±0.1, mN/mg). HF rats displayed increased cavernosal relaxation to sodium nitroprusside (Sham: 57.8±3.4 vs HF: 76.5±5.7, % of relaxation), but no changes were observed in nonadrenergic‐noncholinergic‐ (NANC)‐induced relaxation. Conclusion Our results suggest that increased contractility of the cavernosal tissue in HF rats may represent the mechanism of ED associated with HF.