Effect of partial exchange transfusion with crosslinked hemoglobins on rat renal function

Tetrameric crosslinked hemoglobins (XLhb) are retained in the vascular space longer than unmodified hemoglobin and may be useful as O₂-carrying blood substitutes. This study was performed in order to determine the effects of exchange transfusion of 25-40% blood volume with 6% XLHb on renal function in the anesthetized rat. Exchange with 6% albumin served as the control. Clearance of inulin and p-aminohippuric acid was used to indicate glomerular filtration rate (GFR) and effective renal plasma flow (ERPF), respectively. After transfusion, plasma XLHb was in the range of 25 mg/ml,and hematocrit ranged from 20 to 30%. GFR, urine flow, and Na and K excretion increased following both albumin and XLHb infusion. It is concluded that renal function was not adversely affected for at least 120 min in the presence of 25 mg/ml of XLHb in the plasma and was similar to that occurring following infusion of albumin. It appears that the transient increases in renal function parameters were not due to the transfusion per se, but may result from changes in blood pressure or decreased blood viscosity.