模拟高原低氧环境下运动疲劳大鼠脑皮层单羧酸转运蛋白的变化及其意义  

Changes in Expression of Monocarboxylate Transporters in the Rat Cerebral Cortex after Exercise-induced Fatigue Under Simulated High-altitude Hypoxia and its Significance

作　　者：高晨 凡春玲 李玉荣 裴文娟 关彩萍 GAO Chen;FAN Chunling;LI Yurong;PEI Wenjuan;GUAN Caiping(Department of General Practice,The 94oth Hospital of Joint Logistics Support Force of Chinese People's Liberation Army,Lanzhou730050,.China)

机构地区：[1]联勤保障部队第九四〇医院全科医学科,兰州730050

出　　处：《实验动物与比较医学》2022年第5期384-392,共9页Laboratory Animal and Comparative Medicine

基　　金：甘肃省自然科学基金“MCTs介导脑乳酸代谢调控对高原低氧环境下运动疲劳干预作用及其机制研究”(20JR5RA600)。

摘　　要：目的探讨高原低氧环境下运动疲劳适应性的产生与大脑皮层乳酸转运及代谢状态的关联性。方法63只清洁级SD大鼠随机分为对照组、常规运动组、急进高原组、高原习服3 d组、高原习服1周组、高原习服2周组及给予乳酸转运体抑制剂组(简称高原抑制剂组)。除对照组外,各组大鼠分别在常压常氧或模拟高原低压低氧条件下建立跑台力竭运动疲劳模型。以平均力竭时间确定大鼠运动疲劳的变化趋势。采用免疫印迹和免疫组织化学法检测运动区皮层单羧酸转运蛋白2(monocarboxylate transporters 2,MCT2)和MCT4的表达。采用尼氏染色进行大脑皮层迟发性神经元病理改变评价,并测定鼠脑乳酸含量。结果急进高原组和高原抑制剂组大鼠平均力竭时间分别为(61.00±6.55)min和(71.25±9.59)min,显著低于常规运动组[(124.75±9.36)min]和高原习服2周组[(100.25±9.74)min,(P<0.05)]。免疫印迹检测提示,高原习服2周组及高原抑制剂组鼠脑运动区皮层MCT2表达水平较对照组明显升高,分别为120.6%和164.4%(P<0.05);MCT4的表达分别为174.6%和168.8%(P<0.05)。免疫组织化学检测印证了免疫印迹结果。模拟高原环境下,各组鼠脑乳酸平均含量较常规运动组[(0.175±0.021)mmoL/g]均明显升高(P<0.05)。病理学评价提示,急进高原组和高原抑制剂组鼠脑皮层平均神经元密度值(每个高倍视野的神经元数量)分别为46.75±8.65和63.50±7.65,较对照组(135.88±8.59)明显降低(P<0.05);高原习服2周组(121.75±16.00)与对照组差异无统计学意义(P>0.05)。结论高原习服后机体对运动疲劳的适应性与脑内MCT2和MCT4表达变化相关联,可作为运动疲劳医学干预的靶点。Objective To explore the correlation between adaptation to exercise-induced fatigue and lactate transport and metabolism in the cerebral cortex under high-altitude hypoxia.Methods A total of 63 SD rats were randomly divided into control,normal exercise,rush-entry-into-altitude,3-day-altitude acclimatization,1-week-altitude acclimatization,2-week-altitude acclimatization,and monocarboxylate-transporter-inhibitor(altitude inhibitor injection)groups.Except for the control group,rats were subjected to exhaustive-load treadmill exercises under either normal pressure and normoxic conditions or low pressure and hypoxic conditions.The average time-to-exhaustion was used to determine variation trends in exercise-induced fatigue.The expression of monocarboxylate transporters(MCT)2 and MCT4 in the cerebral motor cortex was detected using western blotting and immunohistochemistry.The pathological evaluation of neuronal death in the cortex was carried out using Nissl staining,and the lactate content was also determined in rat brains.Results The average time-to-exhaustion in the rush-entry-into-altitude and the altitude inhibitor injection groups were(61.00±6.55)min and(71.25±9.59)min,respectively,which was significantly lower than that in the normal exercise(124.75±9.36)min and the 2-week-altitude acclimatization groups(100.25±9.74)min(P<0.05).Western blotting showed that,compared with the control group,the expression of MCT2 in the motor cortex in the 2-week-altitude acclimatization and the altitude inhibitor injection groups increased significantly by 120.6%and 164.4%(P<0.05),respectively;the expression of MCT4 in the two groups increased significantly by 174.6%and 168.8%(P<0.05).The results of western blotting were confirmed by the results of immunohistochemistry.In the high-altitude environment,the average lactate content in rat brains was significantly higher than that in the normal exercise group[(0.175±0.021)mmol/g,P<0.05].Neuropathological evaluation showed that the average neuronal density[neurons per high power

关 键 词：高海拔 低氧 运动疲劳 单羧酸转运蛋白 乳酸 大脑皮层 大鼠 

分 类 号：G804.7[文化科学—运动人体科学] Q95-33[文化科学—体育学]