Premium
AMILORIDE INDUCES CHANGES IN RAT CAVERNOSAL SMOOTH MUSCLE REACTIVITY
Author(s) -
Claudino Mário Angelo,
Silva Fábio Henrique,
FrancoPenteado Carla Fernanda,
Takeshi Fábio Ikeda,
Lopes Anibal,
Antunes Edson,
De Nucci Gilberto
Publication year - 2011
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.25.1_supplement.808.10
We assessed the role of potassium‐sparing diuretic amiloride (AMI) in rat corpus cavernosum (RCC) smooth muscle reactivity. In RCC concentration‐response curves to phenylephrine (PE), KCl, CaCl 2 , and contractile‐ and relaxant‐responses induced by electrical‐field stimulation (EFS) were obtained in the absence or presence of AMI. Relaxant responses to AMI were obtained in the absence and presence of L‐NAME. Gene‐expressions of potassium‐sparing target were determined in RCC. PE, KCl and CaCl 2 induced concentration‐dependent contractions in the RCC with potencies (pEC 50 ) of 5.31±0.01, 1.30±0.03 and 2.35±0.03, and maximal response (E max ) of 3.65±0.39mN, 2.12±0.25mN and 3.06±0.54mN, respect. AMI reduced both pEC 50 and E max of PE (4.97±0.03; 1.23±0.35mN, respect.), KCl (1.05±0.02; 0.85±0.01mN, respect.) and CaCl 2 (2.08±0.03; 0.54±0.10mN, respect.). EFS‐induced contractions were reduced by AMI. However, EFS‐mediated relaxant responses were increased by AMI. AMI produced concentration‐dependent relaxation in the RCC which were reduced by L‐NAME. Real time PCR demonstrated the presence of Na + /H + and Na + /Ca + exchangers and epithelial sodium channel in RCC. In conclusion, the targets of potassium‐sparing diuretics are expressed in RCC, and this diuretic class induced a reduction in contractile mechanism and a relaxation response in RCC, possibly involving changes in the pH i and [Ca 2+ ] i . FAPESP/CNPq