Medina P, Segarra G, Vila J M, Chuan P, Domenech C, Lluch S
Departamento de Fisiología, Universidad de Valencia, Spain.
Am J Hypertens. 1999 Feb;12(2 Pt 1):188-93. doi: 10.1016/s0895-7061(98)00230-1.
The effects of deamino-8-D-arginine vasopressin (desmopressin), a V2 receptor antidiuretic agonist, were studied in isolated rings from branches of renal arteries obtained from 22 patients undergoing nephrectomy. The rings were suspended in organ bath chambers for isometric recording of tension. In precontracted rings with norepinephrine (10(-6) to 3 x 10(-6) mol/L), desmopressin (10(-11) to 3 x 10(-7) mol/L) caused endothelium-dependent relaxation (81%+/-4% reversal of the initial contraction in arteries with endothelium; 20%+/-4% in arteries without endothelium; P < .05). The relaxation to desmopressin in rings with endothelium was reduced significantly by indomethacin (10(-6) mol/L) and unaffected by the inhibitor of nitric oxide synthase NG-nitro-L-arginine methyl ester (10(-4) mol/L). Two V1 receptor antagonists (a peptidic and a nonpeptidic) had no effect on desmopressin-induced relaxation. However, V2 receptor antagonists (three peptidic and a nonpeptidic) reduced significantly (P < .05) the maximal response to desmopressin. The results of this study show that desmopressin exerts powerful endothelium-dependent relaxation of human renal arteries, probably through stimulation of V2-like receptors that may bring about the release of dilating prostaglandins.
在22例接受肾切除术患者的肾动脉分支所取的离体血管环中，研究了V2受体抗利尿激动剂去氨-8-D-精氨酸加压素（去甲加压素）的作用。将血管环悬挂于器官浴槽中进行张力的等长记录。在去甲肾上腺素（10^(-6)至3×10^(-6) mol/L）预收缩的血管环中，去甲加压素（10^(-11)至3×10^(-7) mol/L）引起内皮依赖性舒张（有内皮的动脉中初始收缩的逆转率为81%±4%；无内皮的动脉中为20%±4%；P<.05）。吲哚美辛（10^(-6) mol/L）显著降低了有内皮血管环对去甲加压素的舒张作用，而一氧化氮合酶抑制剂NG-硝基-L-精氨酸甲酯（10^(-4) mol/L）对其无影响。两种V1受体拮抗剂（一种肽类和一种非肽类）对去甲加压素诱导的舒张无作用。然而，V2受体拮抗剂（三种肽类和一种非肽类）显著降低（P<.05）了对去甲加压素的最大反应。本研究结果表明，去甲加压素对人肾动脉具有强大的内皮依赖性舒张作用，可能是通过刺激类似V2的受体，从而导致舒张性前列腺素的释放。
