Mechanisms of pethidine-induced vasodilatation / 浙江大学学报·医学版

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the vasodilating effects of pethidine, particularly in association with intracellular calcium.</p><p><b>METHODS</b>Aorta rings of Sprague-Dawley rats, with or without endothelium, were prepared in organ bath to measure the vascular tone. Pre-contractions by KCl (80 mmol/L) and phenylephrine (PhE) (10(-6)mol/L) were induced.</p><p><b>RESULTS</b>Pethidine did not alter the resting tension of aorta rings, but produced dose-dependent relaxation in KCl and PhE pre-treated aorta rings with or without endothelium. Pethidine did not change the caffeine-stimulated contraction, and still had similar inhibition in KCl pre-contracted aorta rings after pretreatment with ruthenium red. Pethidine decreased the contractile responses induced by PhE in Ca(2+)-free solution or by adding calcium into Ca(2+)-free solution.</p><p><b>CONCLUSION</b>Pethidine could produce an endothelium-independent vasodilatation in KCl and PhE pre-contracted aorta rings, which is related to inhibition of Ca(2+)entry and IP3-sensitive Ca(2+) release in vascular smooth muscle.</p>