Effects of catestatin on tension of isolated vascular rings in rats

Objective To investigate the effects of catestatin(CST) on isolated vascular ring and the putative mechanisms in rats.Methods By recording the change in the tension of isolated thoracic aortic rings induced by phenylephrine(PE),the effects of CST at various concentrations and the change in the effects following administration of nitric oxide synthase inhibitor L-nitro-arginine-methyl ester.Results Phenylephrine(10-9-10-5 mmol/L) elicited iso-lated thoracic aortic ring contraction in rats in a concentration-dependent manner.CST,when administered at the con-centration of 10-8 to 10-4 mol/L,caused vasodilation depending on its concentration that counteracted the vasoconstric-tion induced by PE(10-6 mmol/L).This vasodilation effect was less competent than that of acetylcholine and sodium nitroprusside at the same concentration and was significantly suppressed by L-nitro-arginine-methyl ester(10-4 mol/L).Conclusion CST may counteract the vasoconstriction effect of PE in a concentration-dependent fashion,which may be partly interpreted by the release nitric oxide induced by the endothelium.