[Polyhemoglobin-based model of an artificial oxygen carrier with functional properties similar to blood]

The principal physicochemical and biochemical characteristics are described of a new artificial oxygen carrier model that represents polyhemoglobin (polyHb) with chemically attached pyridoxal-5'-phosphate (PLP), regulator of reversible hemoglobin (Hb) oxygenation. Owing to PLP attachment, the compound obtained (poly Hb-PLP) possesses the oxygen dissociation properties similar to those of blood thereby eliminating one of the main faults of exoerythrocytic Hb and of its high-molecular-weight derivatives, namely high affinity for oxygen. P50 of polyHb-PLP is shown to be 26-28 mm Hg; the oxygen dissociation curve of a mixture of blood and 12% polyHb-PLP (1 : 1) virtually coincides with the blood curve. The data are presented on autooxidation of polyHb-PLP solutions and its mixtures with plasma and blood under physiological conditions. The weight average and number average molecular masses of polyHb-PLP are 172000 +/- 16000 and 120000 +/- 11000, respectively. The width of the polydisperse model amounts to 1.4 +/0 0.3. The relative viscosity of 11-12% polyHb-PLP is about 2. The model is not toxic when injected to mice and rats in a dose of 3 g/kg bw. The evidence presented indicates that polyHb-PLP holds promise as a prospective blood substitute.