[Nitrite reductase activity of deoxyhemoglobin in diabetes and its correction by nicotinamide]. / Nitrytreduktazna aktyvnist' dezoksyhemohlobinu pry diabeti ta ïï korektsiia nikotynamidom.

The increase of deoxyhemoglobin nitrite-reductase activity was established at streptozotocin-induced diabetes in rats. The deoxyhemoglobin nitrosilation in the streptozotocin-induced diabetic rats was shown to increase the optical density in the aromatic acid region and cause additional absorption peak at 334 nm. The two-week injection of nicotinamide causes reduction in the nitrite reductase activity of the deoxyhemoglobin and the absorption peak at 334 nm disappearance.

[The effect of nicotinamide on the enzymatic activity of the antioxidant defense in experimental diabetes]. / Vplyv nikotynamidu na aktyvnist' fermentiv antyoksydantnoho zakhystu pry eksperymental'nomu diabeti.

Experiments on rats with experimental streptosotocin-induced diabetes have shown intensification of the lipid peroxidation processes and reduction of activity of antioxidant defensive enzymes. The content of G-SH and glutathione peroxidase activity has decreased in comparison with the normal rate by 69% and 28%, respectively. Glutathione reductase activity has risen by 20%. Activity of the antioxidant enzymes (superoxide dismutase, catalase) has reduced and the amount of the final product of lipid peroxidation, MDA has increased. Injection of nicotinamide to diabetic rats (200 mg/1 kg of weight) for 14 days normalized activity of the antioxidant enzyme system and the content of the lipid peroxidation products.

[Correcting effect of nicotinamide on hemoglobin glycosylation in streptozotocin diabetes in rats]. / Korrigiruiushchii éffekt nikotinamida na protsessy glikozilirovanniiagemoblogina pri streptozototsinovom diabete u krys.

Streptozotocin induced diabetes in rats was accompanied by development of hyperglycemia, by increase in the rate of hemoglobin and albumin glycosylation in blood and by elevation of 2,3-diphosphoglycerate content in erythrocytes. Alterations of the dissociation properties and the decrease in Hb P50 value suggested the reduced affinity of hemoglobin to oxygen. Injection of nicotinamide, which is involved in NAD+ biosynthesis, caused a decrease of glucose content in blood, stabilized the content of 2,3-diphosphoglycerate and of glycosylated hemoglobin in erythrocytes. Nicotinamide appears to decrease the rate of hemoglobin glycosylation and enhanced the tissue oxygen utilization under hypoxic conditions.