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Murine and rat cavernosal responses to endothelin‐1 and urotensin‐II
Author(s) -
Carneiro Zidonia Nunes,
Carneiro Fernando Silva,
Giachini Fernanda R.C.,
Lima Victor Vitorino,
Webb R. Clinton,
Tostes Rita C.
Publication year - 2008
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.22.1_supplement.744.14
Subject(s) - endocrinology , medicine , phenylephrine , contraction (grammar) , urotensin ii , agonist , endothelin 1 , endothelin receptor , chemistry , receptor , blood pressure
Endothelin‐1 (ET‐1) and urotensin‐II (U‐II) are the most potent and long‐lasting constrictors of human vessels. Although the cavernosal tissue is responsive to ET‐1, and penile smooth muscle cells not only respond to, but also synthesize ET‐1, no information exists on the effects of U‐II on cavernosal function. Aim: To characterize ET‐1 and U‐II responses on rat and mouse corpora cavernosa. Methods and Results: Male Wistar rats (R) and C57/BL6 mice (M) were used at 13 weeks (n=5 and 6, respectively). Cumulative concentration‐response curves to ET‐1, U‐II and IRL‐1620 (ET B agonist) were performed. ET‐1 induced a rapid and sustained increase in force generation in strips from mice and rats, but no responses to U‐II were observed in the presence or absence of L‐NAME (Figure 1). In addition, contractile responses to U‐II were not observed in strips pre‐stimulated with KCl 20mM. Similarly, IRL‐1620 did not induce cavernosal contraction even in presence of L‐NAME. Although relaxation responses to U‐II were not observed in cavernosal strips pre‐contracted with phenylephrine, IRL‐1620 induced cavernosal relaxation with a bigger response in rats than mice (R: 68±3 vs M: 26±3, %). Conclusion: ET‐1 causes contractile responses on cavernosal strips from rats and mice and ET B receptors activation produce relaxation. In contrast U‐II does not induce contraction or relaxation in corpora cavernosa from mice or rats.