寒冷暴露和运动对肥胖大鼠胰岛素敏感性和血清游离脂肪酸的影响。

Effect of Cold Exposure and Exercise on Insulin Sensitivity and Serum Free Fatty Acids in Obese Rats.

机构信息

College of Exercise and Health, Guangzhou Sport University, Guangzhou, Guangdong Province, CHINA.

Institute for Health and Sport, Victoria University, Melbourne, VIC, AUSTRALIA.

出版信息

Med Sci Sports Exerc. 2023 Aug 1;55(8):1409-1415. doi: 10.1249/MSS.0000000000003173. Epub 2023 Mar 14.

DOI:10.1249/MSS.0000000000003173

PMID:36924336

Abstract

PURPOSE

This study aimed to explore the effect of exercise and cold exposure on insulin sensitivity and the level of serum free fatty acids (FFA) in diet-induced obese rats.

METHODS

Sixty-four diet-induced obese rats were randomly assigned to eight groups: room temperature-sedentary, room temperature-exercise, acute cold exposure-sedentary, acute cold exposure-exercise, intermittent cold exposure-sedentary, intermittent cold exposure-exercise, sustained cold exposure-sedentary, and sustained cold exposure-exercise. After the interventions, the homeostatic model assessment for insulin resistance (HOMA-IR) values, the level of serum FFA, subcutaneous fat ratio (SFR) and visceral fat ratio, enzyme activities of adipose triglyceride lipase, and lipoprotein lipase (LPL) in inguinal adipose tissue, and protein expression of PGC1-α and p38 MAPK in skeletal muscle were investigated.

RESULTS

We found that exercise ( P = 0.0136) and cold exposure ( P < 0.0001) reduced HOMA-IR values independently. Exercise reduced serum FFA ( P = 0.0041), whereas cold exposure did not affect them. Moreover, the HOMA-IR values were positively correlated with the serum FFA levels ( r = 0.32, P = 0.01). SFR or visceral fat ratio was coordinately reduced by the interaction (for SFR, P = 0.0015) or opposing main effects between or of cold exposure and exercise, supporting the reduction of serum FFA. However, cold exposure or exercise increased the activity of adipose triglyceride lipase and LPL independently or interactively (for LPL, P = 0.0143), suggesting an increase in serum FFA. Finally, cold exposure and exercise enhanced protein expression of PGC1-α and p38 MAPK independently or interactively (for p38 MAPK, P = 0.0226), suggesting increased uptake and oxidation of serum FFA in muscle.

CONCLUSIONS

These results suggest that the combination of exercise and cold exposure may result in more serum FFA utilization than production and thus lead to reduced serum FFA and increased insulin sensitivity.

摘要

目的

本研究旨在探讨运动和冷暴露对饮食诱导肥胖大鼠胰岛素敏感性和血清游离脂肪酸（FFA）水平的影响。

方法

将 64 只饮食诱导肥胖大鼠随机分为 8 组：室温安静组、室温运动组、急性冷暴露安静组、急性冷暴露运动组、间歇性冷暴露安静组、间歇性冷暴露运动组、持续冷暴露安静组和持续冷暴露运动组。干预后，检测各组大鼠胰岛素抵抗的稳态模型评估（HOMA-IR）值、血清 FFA 水平、皮下脂肪比（SFR）和内脏脂肪比、腹股沟脂肪组织中脂肪甘油三酯脂肪酶和脂蛋白脂肪酶（LPL）的酶活性以及骨骼肌中过氧化物酶体增殖物激活受体γ共激活因子 1-α（PGC1-α）和 p38 丝裂原活化蛋白激酶（p38 MAPK）的蛋白表达。

结果

我们发现运动（P=0.0136）和冷暴露（P＜0.0001）均可独立降低 HOMA-IR 值。运动降低了血清 FFA（P=0.0041），而冷暴露对其没有影响。此外，HOMA-IR 值与血清 FFA 水平呈正相关（r=0.32，P=0.01）。SFR 或内脏脂肪比的降低与冷暴露和运动之间的相互作用（SFR，P=0.0015）或主效应呈协同关系，支持了血清 FFA 的减少。然而，冷暴露或运动可独立或相互作用地增加脂肪甘油三酯脂肪酶和 LPL 的活性（LPL，P=0.0143），提示血清 FFA 的增加。最后，冷暴露和运动可独立或相互作用地增加 PGC1-α 和 p38 MAPK 的蛋白表达（p38 MAPK，P=0.0226），提示肌肉中血清 FFA 的摄取和氧化增加。