Renal Hemodynamic Effects of Contrast Media

Abstract

Dye dilution measurements of renal blood flow were made before and immediately following selective injections (0.3 ml/kg) of contrast media into the renal artery of anesthetized dogs. The materials studied were 50% sodium diatrizoate, 60% meglumine diatrizoate and 60% meglumine iothalamate. NaCl solutions served as isotonic (0.9%) and hypertonic controls (4.5%). The data show a transient 10 to 20% decrease in renal blood flow after each of the contrast media and 4.5% NaCl, whereas physiologic saline produced no significant change. Aortic and renal artery pressure did not change significantly. It is concluded that injection of a hypertonic solution into the renal artery is sufficient to cause a lowering of renal blood flow. The bolus effect, sodium content and pH of the injected agents were eliminated as major determinants of this phenomenon. The extent to which the N-methylglucamine cation and the organic triiodinated molecule contributed to the response was not established. Measurements of appearance time and mean transit time revealed no evidence of major intrarenal shunting.