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

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.