Background. The introduction of chemicals into various types of industry, everyday life, crop production and science provides a back- ground for the development of methemoglobinemia. As a preparation capable of restoring cell metabolism under conditions of hypoxia, we offer the blood substitute rheoambrasol with antihypoxic, antioxidant and detoxification efficacy, developed at the Republican Specialized Scientific and Practical Medical Center for Hematology of the Ministry of Health of the Republic of Uzbekistan.
Objective. Evaluation of the effect of rheoambrasol on the indicators of endogenous intoxication in nitrite-induced methemoglobinemia.
Methods. Toxic methemoglobinemia in rats was created by daily administration of sodium nitrite at a dose of 50 mg/kg for 30 days. During the setting of the model of methemoglobinemia, the methemoglobin (metHb) level was determined one hour after the adminis- tration of sodium nitrite, on the 3rd, 15th and 30th days. On the 30th day after the reproduction of methemoglobinemia, rats were treated with blood substitutes at a dose of 10 ml/kg for 5 days: new blood substitute rheoambrasol in the experimental group and rheopolyglucin in the comparison group. Indicators of endogenous intoxication were determined during the experiment.
Results. The study showed that the use of rheoambrasol effectively reduces the metHb level and restores the indicators of endogenous
intoxication in experimental methemoglobinemia to the initial values. Compared with the results after the use of rheopolyglucin, one hour after the administration of the new blood substitute rheoambrasol, the sorption capacity of erythrocytes (SCE) was lower by 28.9% (p<0.05), plasma middle molecules (MMpl) – by 29.0% (p<0.05), plasma oligopeptides (OPpl) – by 20.6% (p<0.05), middle molecules (MMer) – by 22.5% (p<0.01), erythrocyte oligopeptides (OPer) – by 25.5% (p<0.01), plasma toxemia index (TIpl) – by 43.6% (p<0,01), erythrocyte toxemia index (Tier) – by 41.8% (p<0.01), intoxication index (II) – by 42.8% (p<0.01), MMpl/MMer – by 8.4% (p<0.05).
Conclusions. The new blood substitute rheoambrasol restores metHb level in long-term nitrite-induced methemoglobinemia. Reoambrasol has a pronounced detoxification effect, which manifested itself in a decrease in endogenous intoxication with prolonged nitrite-induced methemoglobinemia and indicators of endogenous intoxication were restored almost to the initial level.

Keywords: MMpl/MMer ratio, intoxication index (II), plasma and erythrocyte middle molecules (MMpl and MMer), sorption capacity of erythrocytes (SCE), methemoglobin, nitrite methemoglobinemia, rheoambrasol