Hemoglobin-albumin clusters as an artificial O-2 carrier: Physicochemical properties and resuscitation from hemorrhagic shock in rats

A bovine hemoglobin (HbBv) or human adult hemoglobin (HbA) wrapped covalently by human serum albumins (HSAs), hemoglobin-albumin clusters (HbBv-HSA(3) and HbA-HSA(3)), are artificial O-2 carriers used as a red blood cell substitute. This article describes the physicochemical properties of the HbBv-HSA(3) and HbA-HSA(3) solutions, and their abilities to restore the systemic condition after resuscitation from hemorrhagic shock in anesthetized rats. The HbBv-HSA(3) and HbA-HSA(3), which have high colloid osmotic activity, showed equivalent solution characteristics and O-2 binding parameters. Shock was induced by 50% blood withdrawal. Rats exhibited hypotension and significant metabolic acidosis. After 15 min, the rats were administered shed autologous blood (SAB), HbBv-HSA(3), HbA-HSA(3), or Ringer's lactate (RL) solution. Survival rates, circulation parameters, hematological parameters, and blood gas parameters were monitored during the hemorrhagic shock and for 6 h after administration. All rats in the SAB, HbBv-HSA(3), and HbA-HSA(3) groups survived for 6 h. The HbBv-HSA(3) and HbA-HSA(3) groups restored mean arterial pressure after the resuscitation. No remarkable difference was observed in the time courses of blood gas parameters in any resuscitated group except for the RL group. Serum biochemical tests showed increases in aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in the HbBv-HSA(3) and HbA-HSA(3) groups compared to the SAB group. Therefore, we observed other rats awakened after resuscitation with HbA-HSA(3) for 7 days. The blood cell count, AST, and ALT recovered to the baseline values by 7 days. All the results implied that HbBv-HSA(3) and HbA-HSA(3) clusters provide restoration from hemorrhagic shock as an alternative material for SAB transfusion.