Iodinated contrast induced renal vasoconstriction is due in part to the downregulation of renal cortical and medullary nitric oxide synthesis

This study suggests that clinically relevant cortical and medullary vasodilators (NO and vasodilator prostanoids) are required to maintain microvascular renal cortical and medullary blood flow. This study combines in vivo techniques of microdialysis and laser Doppler flow probes to show that endogenous NO synthesis is important in serving a protective role to prevent vasoconstriction at the local cortical and medullary levels after radiocontrast administration. Understanding the mechanisms of contrast-induced nephropathy will help develop treatment regimens to either minimize or eliminate this important complication of contrast agents.