Benabe J E, Cruz-Soto M A, Martínez-Maldonado M
Am J Physiol. 1984 Mar;246(3 Pt 2):F317-22. doi: 10.1152/ajprenal.1984.246.3.F317.
Intra-arterial infusion of vanadate (VO4) in dogs produces a reduction in renal blood flow (RBF), glomerular filtration rate (GFR), urine flow (V), and the fractional excretion of sodium (FENa+). To evaluate the role of Ca2+ in these changes VO4 was infused into the renal artery in the presence of the calcium antagonists trifluoperazine (TFP), verapamil, or EGTA. TFP inhibited the effect of VO4 on RBF (TFP + VO4:64.1, VO4:38.5 ml/min; P less than 0.05), GFR (TFP + VO4:22.9, VO4:9.3, ml/min; P less than 0.05) and V (TFP + VO4: 0.80, VO4: 0.38 ml/min; P less than 0.05) without changing FENa+ (TFP + VO4: 3.8, VO4: 3.2%). Similar changes were obtained with verapamil as well as with EGTA. Furthermore thyroparathyroidectomy (TPTX) decreased serum calcium (control: 8.78, TPTX: 4.98 mg/100 ml; P less than 0.05) and blunted the effects of VO4 on renal hemodynamics. Reestablishing normal serum Ca2+ by an intra-arterial infusion of CaCl2 elicited the VO4 effects of vasoconstriction and decreased GFR; V was not affected and FENa+ rose. The data support the idea that influx of extracellular calcium into smooth muscle cells mediates the hemodynamic effects of VO4 in the dog.
给犬肾动脉内输注钒酸盐（VO4）会导致肾血流量（RBF）、肾小球滤过率（GFR）、尿流量（V）和钠分数排泄率（FENa+）降低。为评估Ca2+在这些变化中的作用，在存在钙拮抗剂三氟拉嗪（TFP）、维拉帕米或乙二醇双（2-氨基乙基）醚四乙酸（EGTA）的情况下，将VO4注入肾动脉。TFP抑制VO4对RBF（TFP + VO4：64.1，VO4：38.5 ml/分钟；P<0.05）、GFR（TFP + VO4：22.9，VO4：9.3 ml/分钟；P<0.05）和V（TFP + VO4：0.80，VO4：0.38 ml/分钟；P<0.05）的影响，而不改变FENa+（TFP + VO4：3.8，VO4：3.2%）。维拉帕米和EGTA也得到了类似的变化。此外，甲状旁腺切除术（TPTX）降低了血清钙（对照：8.78，TPTX：4.98 mg/100 ml；P<0.05），并减弱了VO4对肾血流动力学的影响。通过动脉内输注氯化钙使血清Ca2+恢复正常，引发了VO4的血管收缩作用和GFR降低；V未受影响，FENa+升高。这些数据支持这样的观点，即细胞外钙流入平滑肌细胞介导了VO4对犬的血流动力学效应。
