Role of endothelium in enhancement ofα1-adrenoceptor-mediated vasoconstriction by bupivacaine in isolated rat aorta / 中国药理学通报

ABSTRACT

Aim To investigate the role of endothe-lium in the enhancement of phenylephrine-mediated vasoconstriction by bupivacaine in the isolated rat aor-ta.Methods The isolated rat aortic rings were pre-pared, and the vascular endothelium was removed chemically or physically .Phenylephrine-mediated vas-oconstriction was recorded .Results A pretreatment with bupivacaine at 30 μmol · L-1 for 20 min signifi-cantly increased the Emax value of vasoconstrictive re-sponses to phenylephrine from 2.22 ±0.07 g of sol-vent-controlled group to 2.50 ±0.05 g ( P0.05 ) .A pretreatment with bupivacaine at 30 μmol · L-1 for 20 min slightly but significantly inhibited the vasoconstrictive responses to low concen-tration of phenylephrine in the isolated endothelium-de-nuded rat aorta (P0.05 ) .Conclusion Bupivacaine enhances α1-adre-noceptor-mediated vasoconstriction by inhibiting vascu-lar endothelium in the isolated endothelium-intact rat aorta, Which potentiates indirectly the vasoconstrictive responses to phenylephrine .