Study The Role Of Vascular Ring Tension And Mechanisms Catechol Endostatin On Rat

ObjectiveBy measuring the tension of isolated thoracic aortic rings, observe the effects of CST in the tension of that induced by PE and the change following administration of L-Nitro-Arginine-Methyl ester(L-NAME),compared with acetylcholine (Ach) and sodium nitroprusside(SNP), to investigate the effects of catestatin and to deduce the mechanisms of CST.Methods①Prepare the isolated vascular rings of rat, record the tension change after using the phenylephrine (PE) with Powerlab system.②Observe the effects of CST at various concentrations in the tension of isolated thoracic aortic rings induced by PE.③Observe the effect change of CST following administration of L-Nitro-Arginine-Methyl ester(L-NAME),Compared with the classic endothelium dependent and independent reagents:acetylcholine (Ach) and sodium nitroprusside(SNP), to deduce the mechanisms of CST.Results①PE(10-9-10-5mmol/L) elicited isolated thoracic aortic rings contraction in rats in a concentration-dependent manner.②CST, when administered at the concentration of10-8to10-4mol/L, caused vasodilation depending on its concentration that counteracted the vasoconstriction induced by PE (10-6mmol/L). This vasodilation effect was less competent than that of acetylcholine(Ach) and sodium nitroprusside(SNP) at the same concentration.③The vasodilation effect of CST was significantly suppressed by L-NAME. that of Ach was disappeared, and of SNP was not obviously influenced.Conclusion①CST counteract the vasoconstriction effect of PE in a concentration-dependent fashion. ②The mechanism of CST is different from the fully endothelial dependent reagent Ach and the fully endothelial independent reagent SNP.③The effect of CST may be partly interpreted by the release nitric oxide induced by the endothelium.