Abstract: Objective To measure the contractive response of different receptor agonists on the endothelium-denuded caudal artery rings in rats and evaluate the function of different receptors in peripheral resistant vessels. Methods The rat isolated caudal artery rings were prepared, and the vasoconstriction induced by various concentrations of noradrenaline(NA), α,β-MeATP and uridine adenosine tetraphosphate(Up4A)was measured. Results The three receptor agonists could produce concentration-dependent contraction, and the response intensity was NA>α, β-MeATP>Up4A, the values of contraction induced by 10 μmol/L NA, α, β-MeATP and Up4A in caudal artery rings were(95.26 ±14.57)%,(62.28 ±6.98)% and(12.16 ±2.19)% of the maximum contraction induced by KCl, respectively. Conclusion Adrenergic receptors and purinergic receptors may play important roles in the regulation of peripheral resistant vascular tension. The dinucleotide Up4A with pyrimidine and purine structures has the weaker role in mediating peripheral resistant vascular tension. The different vascular tension mediated by different receptors on the peripheral resistance vascular smooth muscle may have significant implications for blood redistribution and ensuring blood supply to important organs.

Key words: receptor agonist, vasoconstriction, purine receptor, adrenoceptor