Les transporteurs d'oxygène à base d'hémoglobine

Abstract

The modified hemoglobins are not true blood substitutes because they do not possess the complex functions of erythrocytes. They are oxygen carriers only with a short intravascular life, adapted for temporary use. Three types of modified hemoglobin solutions have been designed, prepared from human or bovine hemoglobin or by genetic engineering. These hemoglobins are highly purified to eliminate trace amounts of stroma, lipids and endotoxins, which are responsible for acute toxicity. They are modified by internal cross linking between the monomers, or by binding to macromolecules. Afterwards, they can be polymerized or encapsulated in liposomes. The purpose of these modifications is to increase oxygen delivery to tissue, to reduce the dissociation into monomers and to guard against oxydation into methemoglobin. The modified hemoglobin solutions are essentially used in hemorrhagic shock and perioperative hemodilution. These oxygen carriers could be used by some athlets to increase their results in particular during endurance sports. But these hemoglobins are different enough from physiologic hemoglobins (normal or pathological), so they could be easily detected in blood samples.