Morphologic effects following massive exchange transfusions with a stroma-free hemoglobin solution. I. Liver.

Hepatic morphology was studied in rats that were exchange transfused with either a stroma-free hemoglobin solution (SFHS) or with various asanguineous resuscitative fluids. The animals under-went 75 per cent blood volume replacement and tissues were collected and fixed at timed intervals after the exchange transfusion. In addition, blood volumes were determined, using chromium labeled red blood cells, in both albumin and SFHS-treated rats at varying time periods after exchange transfusion. One hour following exchange transfusion, livers of animals infused with asanguineous fluids demonstrated marked centrolobular hepatocellular vacuolization and mitochondrial shape alterations consistent with the effects of hypoxia. SFHS appeared to protect the liver from these early abnormalities. However, at later time intervals livers of albumin-treated animals appeared normal, whereas those of SFHS-transfused rats exhibited centrolobular necrosis. Blood volume was reduced approximately 10 per cent during the first 18 hours after exchange transfusion with albumin, while SFHS-treated rats experienced a 42 per cent blood volume decrement in only 6 hours. Blood volumes were near normal in all animals by 48 hours. These findings suggest that SFHS protects the liver from hypoxia immediately after exchange transfusion, presumably by its ability to transport and release oxygen. However, the eventual disappearance of hemoglobin from the intravascular space is associated with a marked reduction in blood volume which is accompanied by hepatic ischemia and centrolobular necrosis.