Lymphocyte RNA improves microcirculation in intensively working skeletal muscles

Abstract

Aim: To demonstrate the significance of lymphoid RNA regulatory mechanisms for maintaining blood flow in the microvasculature of intensively working skeletal muscles. Methods. Male Wistar rats were divided into 3 groups of 6 animals each: group 1, intact rats; group 2, exercising rats; group 3, exercising rats injected with RNA. The exercise was 6-week swimming, the duration of which was increased every week by 5 minutes (total from 30 to 55 min). RNA was isolated from spleen lymphocytes of 30-day-old pigs and administered to exercising rats at a dose of 30 μg/100 g (4 injections one week apart). The state of the microvasculature was assessed by laser flowmetry. The pattern of microcirculation changes was described with standard and normalized amplitude-frequency indices in different ranges. Results. Compared with group 1, the blood flow variation coefficient increased by 1.2 times in group 2 and by 1.8 times in group 3. Compared with group 1, the shunt coefficient decreased by 23.1% in group 2 and by 44.4% in group 3. Compared with group 1, the arteriolar tone did not change in group 2 and increased by 1.3 times in group 3. Compared with group 1, the microcirculatory bed resistance coefficient did not change in group 2 and decreased by 23.1% in group 3. The myogenic regulation index was similar in all groups. The neurogenic component of regulation increased by 1.5 times in group 2 and by 2.1 times in group 3 compared with group 1. The endothelium-dependent component of regulation increased by 1.4 times in group 3 compared to group 1. The effects of respiratory rhythm and pulse waves were similar in all groups. Conclusion. Lymphocyte RNA helps maintain blood flow stability and increase the adaptive capabilities of vascular tone regulation in the microcirculatory bed of intensively working skeletal muscles.