Cellular and renal toxicity of a urographic contrast medium used in high concentration in uremic patients

The potential toxicity of the urographic contrast medium sodium iothalamate (Conray) has been tested after a bolus injection of 160 ml (66 g iodine) on patients with advanced renal insufficiency. Experiments were performed to investigate the effect of uremic plasma from 5 patients sampled before and after contrast injection on human mononuclear phagocytes cultured in vitro. To investigate the nephrotoxicity, endogenous creatinine clearance was measured before, during and after urography in 25 patients with advanced renal insufficiency (group 1) and in 9 transplanted patients with chronic kidney rejection (group 2). Uremic plasma did not exert further depressive effect on the mononuclear phagocytes after contrast injection when compared to normal plasma indicating no toxicity on this cell model. Neither did the contrast injection exert any depressive effect on creatinine clearance in any of the groups indicating no measurable nephrotoxicity. The urographic technique, particularly the control of fluid balance is found to be very important.