Relationship of Renal Hemodynamic and Functional Changes Following Intravascular Contrast to the Renin–Angiotensin System and Renal Prostacyclin in the Dog

Abstract
Deterioration in renal function has been observed after the use of intravascular contrast media. In an attempt to identify factors responsible for this phenomenon, meglumine iothalamate (Conray 60®), in a dosage range of 2.5-3.3 ml/kg, was injected as a bolus into the aorta of dogs. Serial measurements were made of parameters of renal function as well as of changes in aortic and renal venous levels of angiotensin II, renin activity, and 6-keto-PGF, the stable metabolite of prostacyclin. The major findings were (1) an initial, brief increase followed by approximately a 20% sustained decrease in renal blood flow and creatinine clearance, (2) no significant changes in angiotensin II and renin levels, and (3) a significant decline in the renal secretory rate of 6-keto-PGF. These observations suggest that the suppression of prostacyclin, rather than the activation of the renin-angiotensin system, may contribute to the renal function changes attending the use of intravascular contrast media.