模拟高原训练动物模型的建立(英文)

Establishment of animal model of stimulating altitude training

背景:高原训练作为一种有效提高机体耐力和速度的训练方法,日益为广大教练员所接受,但高原训练的最适宜海拔高度是高原训练中亟待解决的问题。目的:建立大鼠模拟高原训练模型,观察心肌细胞结构在高原训练中的变化,为高原训练的生理学研究提供科学的动物模型,为运动员高原训练提供更加科学的理论依据。设计:以航空航天医学海拔高度区域划分为依据,将实验动物分成不同海拔高原训练组和各对照组,分别进行形态学、细胞亚细胞电镜观察以及心肌肌钙蛋白T的生化分析,从形态学和生物化学两种途径对大鼠心肌损伤进行全面分析。单位:清华大学体育部运动人体科学实验室。材料:实验于2000-01/2002-12在清华大学运动人体科学实验室完成,选用SD大鼠372只。实验材料包括低压氧舱,日产H-500型透射电镜,血清心肌肌钙蛋白T指标的测试试剂盒。方法:所有大鼠372只先进行1周的适应性游泳训练后,随机分成9大组,54个小组,本文仅对其中6组进行分析,分别为模拟急性高原4000m缺氧训练组(n=32)、缺氧不训练对照组(n=24)、模拟急性高原4000m复氧训练1周组(n=32)、模拟急性高原4000m复氧训练2周组(n=32)、递增高原训练组(n=32)、平原训练对照组(n=24)。除平原训练对照组在正常条件下生活与训练外,其他各组均在模拟高原环境中进行游泳训练,每天1小时,每周训练7天,共训练4周。采用酶联免疫吸附法对大鼠血清心肌肌钙蛋白T指标进行测试与观察,模拟海拔4000m急性缺氧训练4周复氧训练2周的大鼠训练结束后,处死大鼠,取左右心室壁一小块心肌组织,经处理并采用醋酸铀及枸橼酸铅进行双染色后,采用日产H-500型透射电镜对切片进行的超微结构观察。主要观察指标:大鼠在不同海拔高度训练状态下血清心肌肌钙蛋白T指标与心肌超微结构电镜图谱测试及观察结果。结果:选用SD大鼠共计304只,无一只死亡,全部进入结果分析。①各组大鼠体质变化:缺氧训练组与缺氧不训练对照组、平原训练对照组之间的心肌增长率差异都有显著性(P<0.01)。而缺氧不训练对照组与平原训练对照组之间差异也有显著性(P<0.05),缺氧训练组、缺氧不训练对照组以及平原训练对照组的体质增长率分别是:22.41%、28.14%、33.48%,3组比较差异均有显著性(P<0.01～0.05)。②心肌肌钙蛋白T测试结果与统计分析:缺氧训练组和缺氧不训练对照组相比,心肌肌钙蛋白T值差异均有显著性,且随着训练周数的增加,心肌肌钙蛋白T值增大,并且差异有显著性(P<0.01)。在模拟4000m以下海拔进行为期1～4周的高原缺氧训练,各组心肌肌钙蛋白T值从0.09μg/L上升到0.128μg/L。在回到平原复氧训练2周后,各组心肌肌钙蛋白T指标均可逆转到0.09μg/L。③电镜观察结果:海拔4000m急性缺氧训练4周,心肌线粒体结构随训练时间的延长出现轻微肿胀,回平原复氧训练2周的大鼠心室肌纤维粗细肌丝形成的明、暗带清晰分明,肌节排列整齐,肌束之间除了含有成簇或零散分布的糖原颗粒外,还存在大量的线粒体,没有观察到浊肿、空泡变性、溶解坏死及间质水肿等病理现象的发生。结论:大鼠在海拔4000m以下的任何高度上进行训练都是比较安全的。如果用急性直接进入海拔4000m高度进行较大强度运动训练,大鼠心脏亚细胞结构发生轻微损伤,心肌肌钙蛋白T浓度增加,采用递增海拔高度的形式进行训练,对心肌损伤影响较轻,训练后恢复也较快。

BACKGROUND： As a method to effectively improve organic tolerance and velocity, altitude training has been gradually accepted by the coaches, and it is a problem to be solved to find the optimal altitude. OBJECTIVE： To establish rat models of stimulating altitude training, and observe the changes of myocardial cell structure in the altitude training, so as to provide scientific animal models for the physiological studies of altitude training, and provide more scientific theoretical evidence for the altitude training of athletes. DESIGN： Based on the division of altitude region m aerospace medicine, the experimental animals were divided into different altitude training groups and control groups. Morphological characters of cellular and subcellular structures were observed under electron microscope, the biochemical analysis of cardiac troponin T were performed, and then the myocardial injury was comoletelv analyzed from two pathways of morphology and biochemistry. SETTING： Laboratory of Sporls andHuman Sciences, Tsinghua University. MATERIALS： The experiments were carried out in the Laboratory of Sports and Human Sciences, Tsinghua University from January 2000 to December 2002. Totally 372 male SD rats were used. The experimental materials included hypobaric oxygen chamber, Japanese H-500 transmission electron microscope and the kit for testing serum cardiac troponin T index. METHODS： After adaptive swimming training for 1 week, all the 372 rats were randomly divided into 9 groups and 54 subgroups, only 6 groups of them were analyzed in this experiment, including stimulating acute altitude hypoxia training at 4 000 m group （n=32）, hypoxia without training group （n=24）, stimulating acute altitude training at 4 000 m followed by reoxygen training for 1 week group （n=32）, stimulating acute altitude training at 4 000 m followed by reoxygen training for 2 weeks group （n=32）, increasing altitude training group （n=32） and plain training control group （n=24）. Rats in the plain training control group lived and trained in normal conditions, and those in the other groups all trained with swimming in the stimulating altitude environment for 4 weeks. They were trained for 7 days every week, once a day and 60 minutes for each time for 4 weeks. The serum cardic troponin T index of rats was detected and observed with enzyme-linked immunoabsorbent assay （ELISA）. After stimulating acute altitude training at 4 000 m for 4 weeks followed by reoxygen training for 2 weeks, the rats were killed, and a small piece of myocardial tissue was taken from left and right ventricles, then double-stained with uranyl acetate and lead citrate, and the uhrastructure of the sections was observed with Japanese H-500 transmission electron microscope. MAIN OUTCOME MEASURES： The serum cardiac troponin T index of rats trained at different altitude, and the results of spectrum and observation of myocardial uhrastucture under electron microscope were mainly observed. RESULTS： （1） Changes of body mass： The myocardial increasing rate in the hypoxia training group was significantly different from those in the hypoxia without training control group and plain training control group （P 〈 0.01）, and there was also significant difference between the latter two groups （P 〈 0.05）. The increasing rate of body mass was significantly different among the hypoxia training group, hypoxia without training control group and plain training control group （22.41%, 28.14%, 33.48%, P 〈 0.01-0.05）. （2） Results of cardiac troponin T： Compared with the hypoxia without training group, the value of cardiac troponin T in the hypoxia training groups was significantly different, and significantly increased with weeks of training （P 〈 0.01）. below 4 000 m for 1-4 weeks, the During the hypoxia altitude training value of cardiac troponin T ranged increased from 0.09 to 0.128 Iμg/L, and it gradually recovered to 0.09 μg,/L after reoxygen training in plain for 2 weeks. （3） The results of observation under electron microscope showed that after acute hypoxia training at 4000 m for 4 weeks, myocardial mitochondrial structure occurred mild swelling with the prolongation of training, and for the rats received reoxygen training in plain for 2 weeks, the thick and thin myofilaments of myocardial fibers formed light and dark bands were clear and distinct, and the myotomes arranged orderly, besides clustered or scattered glycogen granules, a great amount of mitochondria also existed among muscular bundles, no swelling, degeneration of vacuoles, lysis necrosis, interstitial edema and other pathological changes were observed. CONCLUSION： It is safe to train rats at any altitude below 4000 m. The acute exercise training of great intensity directly at 4000 m will cause the mild injury of cardiac subcellular structure, and the increase of cardiac troponin T concentration. The training by means of increasing altitude has slighter influence on the myocardial injury, and the recovery after training is also faster.