Heart rate variability in female Wistar rats under conditions of different physical activity

Objective: to study the characteristics of heart rate variability in female Wistar rats under conditions of normal wakefulness, moderate physical activity and during recovery. Materials and methods. The study was carried out on 48 female Wistar rats aged 5-6 months. Heart rate variability (HRV) was recorded using Physiobelt 2.5.1 (Neurobotics, Russia). HRV analysis was performed using statistical, geometric, and spectral indicators. Physical activity was created using a two-minute treadmill run at a speed of 15 m/min at an angle of 15°. During the experiment we made 3 records of cardiosignal in each anumal: 1 - before the load, 2 - immediately after the load, 3 - after 15-minute rest. Results. Physical activity led to significant changes in a number of statistical and geometric indexes, but no differences in the spectral indexes of all the records were not found. In this regard, we performed cluster analysis on TP, HF, LF indexes of the record 1 that allowed us to form 2 groups: with low and high spectrum values (LSV and HSV). In each group, we observed significant changes in the values of HRV indexes between the records: in the group with LSV, physical activity led to a change in HR, RRNN, Mo, HF (ms2), LF (ms2, %), VLF (ms2, %), LF/HF, IC, in the group with HSV - HR, RRNN, Mo, Amo, IVR, PAPR, VLF (ms2), LF (%), IC. 15-minute recovery contributed to a further change in the value of HRV parameters. Conclusion. The results of the current study demonstrated that physical activity led to activation of the sympathetic nervous system, mobilization of neurohumoral regulation, as well as a change in the level of regulation of the cardiorhythm from peripheral to the central one. The analysis of HRV parameters in females with LSV and HSV allowed us to establish the features of neurohumoral regulation of the functional state of the organism in groups of animals initially different in spectral characteristics.