Comparison of the Response of the Renal Blood Supply to Acetylcholine and to a Calcium Channel Blocking Agentcomma; Diltiazemcomma; in the Dog

摘要

ABSTRACTGarnic JD, Schulman G, Boxt LM, Denny DF, Blackshear JL, Hollenberg NK, Harrington DP. Comparison of the response of the renal blood supply to acetylcholine and to a calcium channel blocking agent, diltiazem, in the dog. Invest Radiol 1985;20: 824ndash;829.Several vasodilators, including acetylcholine, are capable of inducing maximal renal vasodilatation when infused into the renal artery. Despite substantial interest in the renal vascular response to calcium channel blocking agents, there has been no systematic comparison of any of these agents to an index vasodilator, such as acetylcholine. We compared the renal vascular angiographic response to acetylcholine and diltiazem, infused into the renal artery in graded dosage, in 14 dogs. In eight of the dogs renal blood flow was measured with an electromagnetic flowmeter. At peak, the acetylcholine-induced increase in renal blood flow (155plusmn;25 to 309plusmn;55 ml/min) slightly exceeded that induced by diltiazem (143 plusmn; 13 to 257 plusmn; 58 ml/min). A close correlation was found between the maximal blood flow increase induced by acetylcholine and by diltiazem (R = .95). Dilatation of the intrarenal arterial tree evident on the renal arteriogram was substantially less striking with diltiazem than with acetylcholine in these eight dogs. To ascertain the possible contributing role of the surgery required for blood flow measurement, the two agents were assessed in six additional dogs without blood flow measurement. In these six dogs diltnem and acetylcholine induced essentially identical degrees of renal arterial vasodilalation. It is concluded that diltiazern, the calcium channel blocking agent, produces near maximal renal vasodilatation at the arteriolar level and that responses of more proximal dements of the renal arterial tree, visible during renal arteriography, are sensitive to the conditions of the experiment