Involvement of sodium/calcium exchange in the diclofenac-induced spasmolytic effect on rat uterus.
1. The effect of diclofenac (10-100 microM) on rat uterus contraction and its modification by ouabain (0.1 mM), amiloride (0.1 and 1 mM), ouabain (0.1 mM) plus amiloride (1 mM) and the replacement of sodium by choline have been assayed. 2. Diclofenac produces dose-dependent relaxation of vanadate (0.3 mM)-induced contraction (EC50, 17.3 +/- 1.8 microM). This effect is significantly reduced in choline medium (EC50, 49.1 +/- 4.5 microM) and by ouabain in sodium-medium (EC50, 52 +/- 7 microM). 3. Amiloride displaces, in a dose-dependent way, the diclofenac-induced relaxant effect. However, ouabain plus amiloride did not produce a sinergic effect. 4. Our results suggest that diclofenac produces relaxation of vanadate-induced contraction by activation of Na+/Ca(2+)-exchange.
Perez Vallina
J R
JR
Departamento de Medicina, Facultad de Medicina, Oviedo, Spain.
Menendez Antolin
L
L
Cantabrana
B
B
Sanchez
M
M
Hidalgo
A
A
D000584:Amiloride / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002712:Chlorides / Q000494:pharmacology; D004008:Diclofenac / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D007474:Ion Exchange; D009119:Muscle Contraction; D009126:Muscle Relaxation; D010042:Ouabain / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D012964:Sodium / Q000378:metabolism*; D014599:Uterus / Q000187:drug effects*
D002712:Chlorides; D004008:Diclofenac; D010042:Ouabain; D000584:Amiloride; D012964:Sodium; D002118:Calcium