327 FENOLDOPAM PROTECTS HUMAN RENAL TUBULAR CELLS AGAINST COLD-STORAGE INJURY THROUGH AN HO-1 MECHANISM: STUDIES UTILIZING HO-1 siRNA

We have demonstrated that infusion of donor rats with fenoldopam, a dopaminergic compound that maintains renal blood flow without increasing blood pressure, induces HO-1 expression and protects kidneys against cold-storage injury when transplanted. Since fenoldopam has vascular and other cellular effects, whether the protection is mediated through HO-1 remains uncertain. To test this, renal tubular (RPTE) cells were preincubated with fenoldopam (0-80 μg/mL) for 18 hours and subjected to 4°C cold storage for 24 hours. Fenoldopam significantly reduced cold-storage injury (e.g., % LDH release, mean ± SE, 53.4 ± 1.3 cold control vs. 16.2 ± 0.5 and 2.2 ± 0.2 for 10 and 80 μg/mL fenoldopam respectively (n = 3; p