|（1.Key Laboratory of Adolescent Health Assessment and Exercise Intervention，Ministry of Education，Shanghai 200241，China；2.College of Physical Education and Health，East China Normal University，Shanghai 200241，China)
Abstract: The authors observed the effects of 4-week swimming training on visceral fat tissue chronic inflammation mediated by macrophages in db/db mice, and probed into the working mechanism of exercise-induced anti-inflammation. The authors randomly divided 16 db/db mice and 16 wild littermate mice into corresponding control groups (WC and DC) and exercise groups (WE and DE), let the mice swim 1 hour a day, 5 days a week, for 4 weeks, took epididymis fat pads out of the mice in various groups, separated stromal vascular fraction cells (SVCs) of epididymis fat tissues, analyzed SVCs F4/80+CD11b+CD11c+ and F4/80+CD11b+CD11c- macrophages by means of flow cytometry, determined inflammation related gene expressions by means of RT-PCR, and revealed the following findings: db/db mice’s body mass, epididymis fat content, fasting blood glucose (FBG), SVCs number, F4/80+CD11b+ macrophage number and its percentage in SVCs, F4/80+CD11b+ CD11c+ macrophages number and its percentage increased significantly (P<0.05), their epididymis fat TNF-α, IL-6, iNOS, F4/80 and CD11c mRNA expression increased significantly (P<0.05), their epididymis fat IL-10, CD206 and Arg1 mRNA expression de-creased significantly (P<0.05); the 4-week swimming training significantly increased db/db mice’s body mass (P<0.05), did not significantly change their epididymis fat content, significantly decreased their FBG, SVCs number, F4/80+CD11b+ macrophage number and its percentage in SVCs, CD11c+ macrophage number and its percentage in F4/80+CD11b+ macrophages (P<0.05), significantly decreased their epididymis fat TNF-α, IL-6, iNOS, F4/80, CD11c mRNA expression (P<0.05), and significantly increased their IL-10, CD206 and ARG1mRNA expression (P<0.05); the 4-week swimming training did not significantly change various indexes of wild mice. The said find-ings indicate the followings: 1) as type M1 pro-inflammatory macrophages in epididymis fat of db/db mice in-creases, inflammatory cytokines gene expression increases; 2) the 4-week swimming training effectively reduced the infiltration of macrophages in epididymis fat of db/db mice, reduced type M1 macrophages, promoted type M2 anti-inflammatory macrophage phenotype, thus lowered fat tissue inflammation level.
Key words: sports biochemistry；type 2 diabetes；macrophage；chronic inflammation；swimming training；mouse