Sequential effect of angiographic contrast agent on canine renal and systemic hemodynamics

Abstract

The prolonged effects of angiographic contrast media on systemic hemodynamics, renal function, and solute excretion were compared to saline and mannitol in dogs lightly anesthetized with pentobarbital. Measurements of hemodynamic and renal function were made at intervals from one half hour before to one hour after rapid left ventricular injection. The progressive decline in cardiac output and renal plasma flow, following iothalamate reflected diuresis induced volume depletion since these effects were reversed by replacing urine volume. This latter maneuver did not modify the iothalamate effect on renal solute excretion. Although the rate and pattern of urinary excretion of iothalamate- 131I paralleled mannitol, the magnitude of the iothalamate diuresis significantly exceeded that induced by mannitol. The augmented iothalamate diuresis resulted from an increased urinary content of sodium chloride as confirmed by a significant decrease in tubular chloride reabsorption. Mannitol caused an increased renal plasma flow and a reduced renal vascular resistance, while iothalamate effects were opposite. The effect of iothalamate on renal electrolyte reabsorption may represent a direct effect on renal-tubular sodium transport.