ENDOTHELIN AND ATRIAL-NATRIURETIC-PEPTIDE LEVELS FOLLOWING RADIOCONTRAST EXPOSURE IN HUMANS

Radiocontrast exposure is associated with vasoconstriction of the rena l vascular bed and, in certain circumstances, with acute renal failure . This may be influenced by the volume of contrast infused or underlyi ng disease, such as diabetes or renal failure. Changes in circulating vascular regulators, such as endothelin and atrial natriuretic peptide (ANP), may play a role in the development and/or prevention of acute renal failure. Nineteen patients undergoing arteriographic procedures were divided into two groups: large-volume contrast (greater than or e qual to 150 mL; n = 7) and small-volume contrast (< 150 mL; n = 12). C irculating endothelin levels increased significantly (from 12.3 +/- 1. 1 pmol/L to 19.4 +/- 2.2 pmol/L; P < 0.05) following large-volume cont rast exposure (group 1) but not following small-volume contrast exposu re (group 2) (13.9 +/- 1.7 pmol/L to 12.2 +/- 0.09 pmol/L). ANP levels increased significantly in both groups: 43 +/- 15 pg/mL to 75 +/- 21 pg/mL in group 1 and 33 +/- 16 to 106 +/- 39 pg/mL in group 2. Data fr om an additional eight patients with underlying diabetes mellitus and/ or renal insufficiency also were obtained and were considered separate ly. Endothelin levels were higher at baseline and increased significan tly after contrast (25.7 +/- 5 pmol/L to 55.4 +/- 18 pmol/L) despite t he relatively small average volume of contrast infused (112 +/- 15 mL) . ANP levels were also highest in these patients (211 +/- 43 pg/mL pre contrast and 323 +/- 65 pg/mL postcontrast). No group had a significan t change in serum creatinine following contrast exposure. In conclusio n, large-volume radiocontrast exposure is associated with an increase in both circulating endothelin and ANP levels. patients with underlyin g diabetes or renal insufficiency may have higher baseline levels and a greater tendency to increase endothelin after contrast exposure. Whi le an increase in endothelin may contribute to renal vasoconstriction following radiocontrast exposure, simultaneous increases in ANP may se vere to offset this response and protect against changes in renal func tion. (C) 1997 by the National Kidney Foundation, Inc.