Effect of Physical Activity on Portal Vein Resistance Index

Abstract

INTRODUCTION: In norm, adaptation of an organism to physical exercise is determined by the liver functions that ensure high working capacity. To this end, of a special interest are parameters of portal hemodynamics, in particular, the resistance index (RI) as the main coordinator of the differences in the linear velocity of blood flow between the phases of cardiac cycle. Dosed physical exercise is a relevant way of health improvement for not only practically healthy people, but also for people who have suffered COronaVIrus Disease 2019 (COVID-19), and who were diagnosed with liver damage. Such patients are prescribed physical rehabilitation for their health recovery.
 AIM: To study age-related changes in the portal vein (PV) RI and the effect of physical exercise in the form of forced dosed running on this parameter of the portal hemodynamics in an experiment on rats.
 MATERIALS AND METHODS: In young rats of 14–16-month age, which corresponds to 35–40 years of human age, the age-related changes in the portal vein RI were studied using ultrasound Dopplerometry. In animals of the control group, PV RI was studied during 75-day observation, in the experimental group — in the course of daily forced, dosed running on the 1st day, after 15, 30, 45 and 60 days, and also in 15 days after cessation of physical exercise. The actual effect of physical exercise on the change in the PV RI was evaluated with the deduction of age-related changes of the parameter.
 RESULTS: In the animals of the control group, after 60 days of the experiment, the PV RI increased by 5.44 ± 1.22%, and in the experimental group — by 24.10 ± 2.12%. After a 15-day recovery period, the parameter declined, but remained 9.11 ± 0.70% above the initial level. After deduction of the age-related changes of the parameter, the PV RI was 4.36 ± 1.93% above the initial one.
 CONCLUSION: Changes in the PV RI in daily dosed physical exercise did not go beyond the physiological norm and were transient. After a 15-day recovery period, the PV RI practically approached the initial parameter.