Effects of different exercise on liver lipid accumulation and FGF21 secretion in obese rats

doi:10.12047/j.cjap.6209.2022.009

Abstract

Abstract: Objective: To investigate the effects of continuous exercise training (CT) and high-intensity interval exercise training (HIIT) on liver lipid metabolism and the correlation of the level of fibroblast growth factor 21(FGF21) in serum and liver tissues. Methods: Male SD rats were randomly divided into normal diet group (N) and obesity model group (H) after 1 week of adaptive feeding. Rats in the obesity model group were fed with 45% high-fat diet for about 8 weeks, and 20% weight increase compared with normal rats was considered as obesity. The rats were divided into normal diet control group (LC), normal diet HIIT group (LHI), normal diet CT group (LCT), High fat diet-induced obese control group (OC), obese HIIT group (OHI), and obese CT group (OCT) (n=10). Exercised rats were given weight-bearing swimming training intervention for 8 weeks. Blood samples were collected at least 24h after the last exercise intervention to detect the serum levels of inflammatory factors and FGF21. Liver tissue samples were collected to detect the lipid content, lipid metabolic enzyme content and FGF21 expression level. Results: Compared with LC group, the body weight, serum inflammatory factors levels and hepatic triglyceride content were increased significantly (P＜0.05). Hepatic triglyceride content was downregulated in LHI group and FGF21 expression level was enhanced in LCT group (P＜0.05). Compared with OC group, the body weight and hepatic triglyceride content were decreased significantly (P＜0.05), mitochondrial CPT-1β and β-HAD enzyme contents in liver were increased significantly (P＜0.05) in OHI group, the contents of LPL and FAT/CD36 enzyme in liver and the levels of FGF21 in serum and liver of OCT group were increased significantly (P＜0.05). Conclusion: Both exercise modes can reduce the body weight in normal and obese rats, and lipid deposition in the liver of obese rats. HIIT has a more significant effect on alleviating liver lipid deposition in obese rats by upregulating mitochondrial lipid oxidation level in normal and obese rats. CT improves the levels of FGF21 in serum and liver tissues of normal and obese rats, enhances enzyme contents that involved in fatty acids uptake to the liver, which has limited effect on alleviating lipid deposition in liver of obese rats.

Key words: obesity, rats, high-intensity interval exercise, continuous exercise, liver lipid metabolism, fibroblast growth factor 21

CLC Number:

G804.2

ZHANG Yuan, SHENG Lei, LIU Xiao-wei, WEI Juan, LIU Xiu-juan, ZHANG Nian-yun, WANG Zi-yi. Effects of different exercise on liver lipid accumulation and FGF21 secretion in obese rats[J]. CJAP, 2022, 38(1): 47-52.

References

[1] Tsunoda K, Kai Y, Kitano N, et al. Impact of physical activity on nonalcoholic steatohepatitis in people with nonalcoholic simple fatty liver: A prospective cohort study[J]. Prev Med, 2016, 88: 237-240.
[2] Sozio MS, Liangpunsakul S, Crabb D. The role of lipid metabolism in the pathogenesis of alcoholic and nonalcoholic hepatic steatosis[J]. Semin Liver Dis, 2010, 30(4): 378-390.
[3] Gimeno RE, Moller DE. FGF21-based pharmacotherapy--potential utility for metabolic disorders[J]. Trends Endocrinol Metab, 2014, 25(6): 303-311.
[4] Hallsworth K, Thoma C, Hollingsworth KG, et al. Modified high-intensity interval training reduces liver fat and improves cardiac function in non-alcoholic fatty liver disease: a randomized controlled trial[J]. Clin Sci (Lond), 2015, 129(12): 1097-1105.
[5] Cassidy S, Thoma C, Hallsworth K, et al. High intensity intermittent exercise improves cardiac structure and function and reduces liver fat in patients with type 2 diabetes: a randomised controlled trial[J]. Diabetologia, 2016, 59(1): 56-66.
[6] 朱磊, 路瑛丽, 冯连世, 等. 不同配方高脂饲料构建SD大鼠肥胖模型的实验研究[J]. 中国运动医学杂志, 2016, 35(7): 642-647.
[7] Da RG, Crisp AH, de Oliveira MR, et al. Effect of high intensity interval and continuous swimming training on body mass adiposity level and serum parameters in high-fat diet fed rats[J]. Scientific World Journal, 2016, 1(2194120): 1-8.
[8] Duggan GE, Hittel DS, Sensen CW, et al. Metabolomic response to exercise training in lean and diet-induced obese mice[J]. J Appl Physiol (1985), 2011, 110(5): 1311-1318.
[9] 赵述强, 时洪举, 郑宁宁. 6周不同强度间歇性运动对肥胖大鼠体成分的影响[J]. 中国应用生理学杂志, 2019, 35(4): 326-330.
[10] Wang N, Liu Y, Ma Y, et al. High-intensity interval versus moderate-intensity continuous training: Superior metabolic benefits in diet-induced obesity mice[J]. Life Sci, 2017, 191: 122-131.
[11] Vella CA, Taylor K, Drummer D. High-intensity interval and moderate-intensity continuous training elicit similar enjoyment and adherence levels in overweight and obese adults[J]. Eur J Sport Sci, 2017, 17(9): 1203-1211.
[12] Saltiel AR, Olefsky JM. Inflammatory mechanisms linking obesity and metabolic disease[J]. J Clin Invest, 2017, 127(1): 1-4.
[13] Selvaraju V, Bahu JR, Geetha T. Association of salivary C-reactive protein with the obesity measures and markers in children[J]. Diabetes Metab Syndr Obes, 2019, 12: 1239-1247.
[14] Hodson L, Rosqvist F, Parry SA. The influence of dietary fatty acids on liver fat content and metabolism[J]. Proc Nutr Soc, 2020, 79(1): 30-41.
[15] Nd AM. Non-alcoholic fatty liver disease, an overview[J]. Integr Med (Encinitas), 2019, 18(2): 42-49.
[16] 卢漫漫, 陈家耀, 钮鸣宇, 等. 有氧运动对高脂饮食小鼠肝脏中CLK2蛋白表达的影响[J]. 中国应用生理学杂志, 2020, 36(1): 23-26.
[17] Astorino TA, Schubert MM. Changes in fat oxidation in response to various regimes of high intensity interval training (HIIT)[J]. Eur J Appl Physiol, 2018, 118(1): 51-63.
[18] 张洁, 余红艳, 邸阜生. 高强度间歇运动对C57BL/6小鼠高脂饮食诱导肝脏脂肪沉积的影响[J]. 中华肝脏病杂志, 2019(4): 312-315.
[19] Ogrodnik M, Miwa S, Tchkonia T, et al. Cellular senescence drives age-dependent hepatic steatosis[J]. Nat Commun, 2017, 13(8): 1-12.
[20] Fletcher JA, Linden MA, Sheldon RD, et al. Fibroblast growth factor 21 andexercise-induced hepatic mitochondrial adaptations[J]. Am J Physiol Gastrointest Liver Physiol, 2016, 310(10): G832-G843.