Effect of copper aspirinate on contraction of isolated rabbit aortic strips

AIM; To investigate the effect of copper aspirinate on contraction of vascu lar smooth muscle. METHODS: Isolated rabbit aortic strips, including intact endothelium strips and endothelial cell-denuded aortic strips, were suspen ded in modified Krebs solution to determine effects of copper aspirinate on the contraction induced by norepinephrine (NE), KCl, and CaCl2, while CuSO 4, aspirin, and vehicle were used as controls. RESULTS: Copper aspirinate p ossessed antagonistic effect on contraction of rabbit aortic strips induced by NE with an IC50 value of 31 nmol/L, while CuSO4 had much less antagonis tic effect with an IC50 value of 0.29 mu mol/L, and aspirin did not work in the same preparation. No effect of copper aspirinate were found on the con traction induced by KCl and CaCl2. Effects on endothelial cell denuded aort ic strips were similar to those in the normal aortic strips. CONCLUSION: Co pper aspirinate possessed different effects from aspirin and CuSO4 on vascu lar smooth muscles. It inhibited contraction induced by NE with an activity stronger than CuSO4 at the same Cu2+ concentration, this action might be d ue to blockade of the receptor-operated Ca2+ channels, and it might not be linked to the endothelium.