Effects of hemoglobin-based oxygen-carrying solutions in anesthetized rats with acute ischemic renal failure

The effects of three hemoglobin solutions were compared with those of iso-oncotic human serum albumin in rats with ischemic renal failure and sham-operated controls. Unmodified and alpha-alpha cross-linked hemoglobins both increase mean arterial pressure and systemic vascular resistance and reduce cardiac output substantially and to a comparable extent. In contrast, omicron-raffinose cross-linked hemoglobin has no deleterious effect on any of these parameters. In sham-operated rats unmodified hemoglobin reduces the glomerular filtration rate (GFR) by approximately 30%, whereas neither of the two cross-linked hemoglobins has any adverse effect on GFR in this group. None of the three hemoglobin solutions exacerbated the degree to which GFR was reduced by ischemia-reperfusion injury. Also, the degree of tubular necrosis induced by ischemia-reperfusion injury was also comparable in all groups. We conclude the following: (1) omicron-raffinose cross-linking, but not alpha-alpha cross-linking, ameliorates the effects of unmodified hemoglobin on vascular resistance and cardiac output; (2) both forms of cross-linking reduce the nephrotoxicity exhibited by unmodified hemoglobin in sham-operated rats; and (3) none of the hemoglobin solutions exacerbate renal injury induced by ischemia-reperfusion.