The effect of photobiomodulation therapy of some indices of rats’ blood cells functional state under experimental diabetes mellitus

Background. Diabetes mellitus is a chronic endocrine-metabolic disease caused by an absolute or relative insulin deficiency. During diabetes, there are perfect conditions for the development of oxidative stress: the content of substrates for oxidation increases, the content of natural antioxidants decreases and the activity of antioxidant systems is suppressed. It is known that photobiomodulation therapy produce antioxidant and antihyperglycemic effects. Here we investigated its influence on blood system functioning. Materials and Methods. The study was performed on male Wistar rats. Experimental diabetes mellitus was induced by the intraperitoneal injection of streptozotocin. Leukocyte formula was calculated using blood smears stained by Romanowsky–Giemsa. Catalase activity was determined spectrophotometrically. Affinity of hemoglobin to oxygen was evaluated by spectrophotometric method in Ivanov’s modification by drawing oxygenation curves. The protoporphyrin content in whole blood was measured by analyzing its fluorescence spectra. The content of NO2-, total and inducible NO synthase activity was determined spectrophotometrically. Results. Under the action of photobiomodulation therapy on healthy animals, there was a shift of oxygenation curves to the left and a decrease of P50, whereas under irradiation of rats with diabetes, there was a shift of oxygenation curves to the right and increase in P50 compared to indices in nonirradiated animals. During diabetes, there was a decrease in protoporphyrin content compared to control, but there was a tendency to increase under photobiomodulation. Photobiomodulation therapy of rats with diabetes increased catalase activity in erythrocyte hemolysates. We revealed significant changes in leukocyte formula under photobiomodulation. The total NO synthase activity in leukocytes of rats with diabetes was higher compared to healthy animals, but decreased under the action of photobiomodulation. We found an increase in inducible NO synthase activity in leukocytes of rats with diabetes and in leukocytes of irradiated healthy animals. An increase in NO2- content in leukocytes of rats with diabetes was detected. Under photobiomodulation, NO2- content was significantly lower in rats with diabetes. Conclusion. Photobiomodulation therapy produces a corrective action on blood system during diabetes, in particular, it improves oxygen release from hemoglobin and prevents hypoxia. Simultaneously with the increase in tissue oxygen saturation, a decrease in NO synthase activity and nitrite content along with an increase in catalase activity prevents the development of oxidative stress.