The Impaired Function of Macrophages Induced by Strenuous Exercise Could Not Be Ameliorated by BCAA Supplementation.

Weihua Xiao,Xiaoguang Liu,Linlin Zhao,Peijie Chen

doi:10.3390/nu7105425

Weihua Xiao, Xiaoguang Liu + Show 2 more

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https://doi.org/10.3390/nu7105425

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Journal: Nutrients	Publication Date: Oct 21, 2015
Citations: 47	License type: CC BY 4.0

Affiliation: Shanghai University of Sport

Abstract

The aim of this study was to evaluate the effect of strenuous exercise on the functions of peritoneal macrophages in rats and to test the hypothesis that branched-chain amino acid (BCAA) supplementation will be beneficial to the macrophages of rats from strenuous exercise. Forty male Wistar rats were randomly divided into five groups: (C) Control, E) Exercise, (E1) Exercise with one week to recover, (ES) Exercise + Supplementation and (ES1) Exercise + Supplementation with 1 week to recover. All rats except those of the sedentary control were subjected to four weeks of strenuous exercise. Blood hemoglobin, serum testosterone and BCAA levels were tested. Peritoneal macrophages functions were also determined at the same time. The data showed that hemoglobin, testosterone, BCAA levels, and body weight in group E decreased significantly as compared with that of group C. Meanwhile, phagocytosis capacity (decreased by 17.07%, p = 0.031), reactive oxygen species (ROS) production (decreased by 26%, p = 0.003) and MHC II mRNA (decreased by 22%, p = 0.041) of macrophages decreased in the strenuous exercise group as compared with group C. However, the chemotaxis of macrophages did not change significantly. In addition, BCAA supplementation could slightly increase the serum BCAA levels of rats from strenuous exercise (increased by 6.70%, p > 0.05). Moreover, the body weight, the blood hemoglobin, the serum testosterone and the function of peritoneal macrophages in group ES did not change significantly as compared with group E. These results suggest that long-term intensive exercise impairs the function of macrophages, which is essential for microbicidal capability. This may represent a novel mechanism of immunosuppression induced by strenuous exercise. Moreover, the impaired function of macrophage induced by strenuous exercise could not be ameliorated by BCAA supplementation in the dosing and timing used for this study.

Highlights

Exercise enhances or reduces immune functions depending on its frequency, duration and intensity
Some studies focus on the relationship between exercise and macrophages, little attention has been paid to the effects of long-term intensive exercise on macrophage functions
The aim of this study is to evaluate the effect of strenuous exercise on the functions of peritoneal macrophages in rats, and to test the hypothesis that Branched-chain amino acid (BCAA) supplementation will be beneficial to the macrophages of rats from strenuous exercise

Summary

Introduction

Exercise enhances or reduces immune functions depending on its frequency, duration and intensity. Regular physical activity is known to enhance immune functions leading to a decrease in the occurrence of infections. Heavy or exhaustive exercise increases the susceptibility to infections [1,2,3]. Exercise increases or decreases the occurrence of infections that may be related to the changes of macrophage functions [4,5]. Monocytes/macrophages are considered to be the frontline of immunological defense against pathogens. These cells have prominent roles such as Ag presentation, chemotaxis, phagocytic, microbicidal, tumoricidal and secretory functions, as well as, innate immunity, by initiating inflammatory and immune responses [6]. Some studies focus on the relationship between exercise and macrophages, little attention has been paid to the effects of long-term intensive exercise on macrophage functions

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