Modulating respiratory mechanics and inflammation in hepatopulmonary syndrome: Aerobic exercise as a therapeutic strategy

Abstract

Introduction

Aerobic exercise training positively modulates the immune system and improves lung function; however, its effects on respiratory system’s elastic, resistive properties and interleukin-10 (IL-10) concentration in hepatopulmonary syndrome (HPS) remains unexplored. This study aimed to assess whether moderate-intensity aerobic (AE) training altered exercise capacity, respiratory mechanics and lung inflammation.

Material and methods

Wistar rats were randomly assigned to SHAM, HPS, HPS + AE4, and HPS + EA8 groups. The EA4 group represents AE training for 4 weeks starting 7 days after HPS induction, whereas EA8 accounts for AE training for 4 weeks before and after HPS induction, both protocols practiced 3 times weekly. Exercise capacity, respiratory mechanics, lung and systemic inflammation, and lung morphology were assessed.

Results

Moderate aerobic exercise significantly increased the maximal running capacity of the HPS animals. The training decreased tissue elastance by 19 % (p = 0.01 compared to SHAM) and reduced frequency-dependent respiratory reactance at 0.5 Hz, 0.75 Hz, and 1.25 Hz frequencies compared to HPS animals (p < 0.05 for all). For the HPS + EA4 and HPS + EA8 groups IL-10 plasma concentration increased by 23 % and 31 % compared to SHAM (p < 0.001 both) and by 38 % and 47 % compared to HPS (p < 0.01 both). Nonetheless, AE did not alleviate lung tissue remodeling induced by HPS.

Conclusions

Moderate-intensity aerobic training improved maximum running capacity, reduced HPS-induced respiratory mechanics derangements at the lung regional level, and increased systemic IL-10 concentration, although it did not ameliorate lung tissue remodeling.