Abstract
<jats:p>Background. The tissue of the small intestine is sensitive to radiation exposure. The key element of the damage is energy metabolism disturbance. Tissue respiration substrates can regulate and protect the mitochondrial oxidation system. Their effect on the energy metabolism of the small intestine in the early stages after irradiation has not been sufficiently studied. Objective. To evaluate the effect of mitochondrial oxidation substrates on the energy metabolism of small intestinal tissue fragments of laboratory rats on the 3rd and 10th days after a single external irradiation at a dose of 0.5 and 1 Gy. Material and methods. Two groups of white male Wistar rats (weight 150-220 g) were irradiated using IGUR-1 facility (source 137Cs) at a dose of 0.5 and 1 Gy (power 0.92 Gy/min). A mixture of succinate and potassium glutamate in gelatin capsules (25 mg/ kg of body weight) was added to the diet of the irradiated animals over the period of 3-10 days. On the 3rd and 10th days, the parameters of mitochondrial oxidation of small intestinal tissue fragments were evaluated using the polarographic method. Results. The introduction of succinate and potassium glutamate over the period of 3 days had a positive effect on energy parameters: the rate of endogenous respiration corresponded to that of the comparison group, the intensity of oxygen consumption on exogenous substrates improved as well. On day 10, the combination of substrates stimulated both endogenous and substrate respiration (p <0.05). The effect was more pronounced in groups with a dose of 1 Gy. Conclusion. The introduction of succinate and glutamate into the diet of irradiated laboratory rats restores energy metabolism in small intestinal tissues due to the replenishment of substrates, thus ensuring a protective effect and preservation of mitochondria.</jats:p>