不同受体激动剂诱发大鼠去内皮尾动脉环的收缩反应

Contractile response of endothelium-denuded caudal artery induced by different receptor agonists in rats

目的测定不同受体激动剂对大鼠去内皮尾动脉环收缩反应,推测外周阻力血管不同受体介导血管张力的作用。方法制备大鼠离体去内皮尾动脉血管环,测定不同浓度去甲肾上腺素(noradrenaline,NA)、α,β-亚甲基三磷酸腺苷(α,β-MeATP)和尿苷腺苷四磷酸盐(uridine adenosine tetraphosphate,Up4A)诱发的血管收缩反应。结果三种受体激动剂均可产生浓度依赖性收缩反应,反应强度为NA>α,β-MeATP>Up4A,10μmol/L NA、α,β-MeATP和Up4A诱发的尾动脉环收缩值分别为KCl最大收缩反应的(95.26±14.57)%、(62.28±6.98)%和(12.16±2.19)%。结论肾上腺素能受体和嘌呤能受体在外周阻力血管张力调节方面具有重要作用;具有嘧啶和嘌呤结构的二核苷酸Up4A在介导外周阻力血管张力方面作用较弱。外周阻力血管平滑肌不同受体介导血管张力的不同可能对血液再分配、保障重要脏器血液供应方面具有重要意义。

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 10μmol/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.