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Alteration in contractile mechanism of rat cavernosal smooth muscle induced by different class‐diuretics
Author(s) -
Claudino Mário Angelo,
Takeshi Fábio Ikeda,
Priviero Fernanda Bruski Marinho,
Antunes Edson,
Lopes Anibal,
De Nucci Gilberto
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.576.4
Subject(s) - hydrochlorothiazide , endocrinology , medicine , amiloride , potassium , furosemide , diuretic , chemistry , thiazide , phenylephrine , stimulation , aldosterone , sodium , blood pressure , organic chemistry
We assessed the involvement of different diuretics in the contractile mechanisms of rat corpus cavernosum smooth muscle (CC). In CC from male Wistar rats, concentration‐responses curves to phenylephrine (PE) and potassium chloride (KCl) and neurogenic contractile responses induced by electrical‐field stimulation (EFS) were obtained in absence (control; CTL) or in presence of furosemide (FUR; loop diuretic), hydrochlorothiazide (HTZ; thiazide) and amiloride (AMI; potassium‐sparing diuretic). PE contracted CC with a potency (pEC 50 ) of 5.51 ± 0.02. FUR and HTZ did not change the pEC 50 of PE (5.54 ± 0.06 and 5.58 ± 0.07, respectively), but significantly increased the maximal responses (E MAX ; 2.97 ± 0.22 and 3.65 ± 0.39 mN, respectively; vs CTL: 2.41 ± 0.10 mN). AMI reduced the pEC 50 of PE (5.37 ± 0.08) with no changes in E MAX (2.48 ± 0.29 mN). KCl contracted CC with a pEC 50 of 1.35 ± 0.10. FUR and HTZ did not alter the pEC 50 of KCl (1.37 ± 0.03 and 1.31 ± 0.08, respectively) but increased E MAX (1.24 ± 0.16 and 1.41 ± 0.06 mN, respectively, vs CTL: 0.65 ± 0.05 mN). AMI decreased pEC 50 of KCl (1.06 ± 0.04) with no changes in E MAX (0.84 ± 0.16 mN). EFS induced frequency‐dependent contractions in CC which were enhanced by FUR and HTZ. AMI reduced EFS‐induced contractions at the highest frequencies (16–32Hz). In conclusion, different diuretics distinctively alter the CC contractions possibly by changing [Ca 2+ ] i and [Cl − ] i content. FAPESP