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61.
老年高血压病左室肥厚与神经体液因素及室性早搏的相关性 总被引：1，自引：0，他引：1
为探讨老年高血压病左室肥厚（LVH）与部分神经体液因素之间的关系及与室性早搏，心肌缺血的相关性，老年高血压病伴左室肥厚60例为A组，单纯老年高;血压病60例为B组，对比观察心率变异，肾素（Ren)，血管紧张素（AT－II），醛固酮（Ald)，胰岛素峰值（Ins),24h动态心电图和血压等指标，结果显示：1）A组病人交感神经张力明显增高，迷走神经活性下降不明显，室性早搏的发生与交感神经张力增高有关；室性早搏与心肌缺血具有相关性；2）A组病人与Ald及Ins水平有关，与Ren和AT－II无明显相关；3）A组病人与室性早搏和心肌缺血明显相关，结论表明，老年高血压病在室肥厚患者交感神经张力增高，Ald及Ins水平升高，与室性早搏，心肌缺血具有正相关。 相似文献
62.
The main determinants of an athlete's protein needs are their training regime and habitual nutrient intake. Most athletes ingest sufficient protein in their habitual diet. Additional protein will confer only a minimal, albeit arguably important, additional advantage. Given sufficient energy intake, lean body mass can be maintained within a wide range of protein intakes. Since there is limited evidence for harmful effects of a high protein intake and there is a metabolic rationale for the efficacy of an increase in protein, if muscle hypertrophy is the goal, a higher protein intake within the context of an athlete's overall dietary requirements may be beneficial. However, there are few convincing outcome data to indicate that the ingestion of a high amount of protein (2–3?g?·?kg?1 BW?·?day?1, where BW?=?body weight) is necessary. Current literature suggests that it may be too simplistic to rely on recommendations of a particular amount of protein per day. Acute studies suggest that for any given amount of protein, the metabolic response is dependent on other factors, including the timing of ingestion in relation to exercise and/or other nutrients, the composition of ingested amino acids and the type of protein. 相似文献
63.
The aim of the present study was to test the hypothesis that upper body aerobically trained athletes (kayak canoeists) would have greater left ventricular wall thickness, but similar left ventricular diastolic chamber dimensions, compared with recreationally active and sedentary men. Ultrasound echocardiography was used to determine cardiac structure and function in highly trained kayak canoeists (n?=?10), moderately active (n?=?10) and sedentary men (n?=?10). The septal and posterior left ventricular walls were ～0.2?cm thicker in kayak canoeists (P?<?0.05), and left ventricular mass was 51% and 32% greater (P?<?0.05) in canoeists than in the sedentary and moderately trained participants, respectively. There were no differences in left ventricular chamber dimension, suggesting that the kayak canoeists had a concentric pattern of left ventricular adaptation to aerobic upper body training. Scaling the data to body composition indices had no effect on the outcome of the statistical analysis. There were no differences in resting Doppler left ventricular diastolic or systolic function among the groups. Ejection fraction was lower in the kayak canoeists, but the magnitude of the difference was within the normal variability for this measurement. Thus aerobically upper body trained athletes demonstrated a concentric pattern of cardiac enlargement, but resting left ventricle function was not different between athletes, moderately active and sedentary individuals. 相似文献
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65.
《European Journal of Sport Science》2013,13(3):238-243
Abstract Exercise to failure results in similar muscle protein synthesis responses, independent of intensity. However, low-intensity exercise likely requires more repetitions and individuals with injuries may be incapable of sustaining the mechanical stress to reach failure. The aim of this study was to determine if knee wraps provide a stimulus to decrease time to failure. Twenty healthy individuals participated in a randomized crossover study consisting of three trials. The first trial was used to determine one-repetition maximum (1-RM) on leg extension. Participants were then assigned to a blood flow restriction or control group. After trial 2, participants crossed over to the opposite trial. Knee wraps were placed around the upper thigh of each leg during blood flow restriction. Leg extensions were completed at 30% 1-RM until failure. A rating of perceived exertion was taken after exercise and whole blood samples were taken before, after, and 3 min after exercise for the determination of lactate. Repetitions until failure and total work were significantly lower with practical blood flow restriction compared with the control trial. Metabolic stress as measured by whole blood lactate was higher immediately after muscular failure in the control compared with the blood flow restriction trial, but not so 3 min after exercise. There were no differences in ratings of perceived exertion. In conclusion, knee wraps provide a stimulus for blood flow restriction allowing failure to occur sooner with similar metabolic stress after reperfusion. However, similar perceptual responses despite the lower workload with blood flow restriction may limit its application to the highly motivated. 相似文献
66.
运动能促进身体组织和器官的有利改变,如运动调控骨骼肌的质量和力量变化。一方面,近期研究认为,细胞信号分子对骨骼肌卫星细胞的状态有决定性作用,如激活、增殖、分化、融合等促进骨骼肌重塑过程;另一方面,运动刺激骨骼肌中生长因子合成和分泌的变化,对骨骼肌细胞信号分子的传递与骨骼肌肥大密切相关。目前,国内外鲜有报道从运动和细胞信号分子交互作用探究运动促进骨骼肌肥大的机制。因此,研究试图对运动和多个细胞信号分子的交互作用进行综述,以期为人体复杂系统中骨骼肌肥大机制提供新的研究思路。 相似文献
67.
通过不同负荷大鼠运动模型的建立，用透射电子显微镜观察了一般游泳训练大鼠及过度负荷大民心肌超微结构变化。结果表明：一般训练组心肌呈与有氧代谢相适应的生理性肥大，主要是心系数增大、线粒体增多；过度负荷组则呈现病理性改变，心肌肌丝断裂，线粒体结构模型、膜破坏，并见扩张的“二联体”结构。结果提示：适宜负荷提高心脏机能，过度负荷使心脏重塑朝病态方向转化。 相似文献
68.
陆建峰 《广州体育学院学报》1997,(2)
通过对60例儿童进行彩色多普勒超声心动图检查,研究单纯性肥胖症儿童的心脏结构和机能的变化,探讨肥胖对儿童期心血管系统的危害性。研究发现8岁肥胖儿童心腔明显增大、心肌已非正常性肥厚,功能表现为高搏出量和高输出量状态。结果表明肥胖不仅是成年人某些严重心脏疾病的潜在危险因素,而且在儿童期已造成心脏结构损害和功能代偿,严重威胁着儿童的身体健康。 相似文献
69.
运动性心肌肥大的机理研究(综述) 总被引：2，自引：0，他引：2
运动性心肌肥大是运动训练中普遍出现的生理现象,其表现为心脏增大,心肌肥厚,心室壁增厚,心脏重量增加等现象.目前,对运动性心肌肥大属调节性、生理性肥大的认识渐趋一致,但其发生机制尚末完全阐明.根据文献报导,从血流动力学因素、神经内分泌因素(如儿茶酚胺、血管紧张素Ⅱ)、致心肌肥大因子、遗传因素等对心肌肥大机理作一综述. 相似文献
70.
运动性与病理性心肌肥大左室肌球蛋白α和β重链变化比较 总被引：7，自引：0，他引：7
对大鼠运动心肌肥大和病理心肌肥大模型心室肌球蛋白α和β重链的变化进行比较研究,结果发现大鼠经10周游泳训练后引起心肌肥大,心室肌球蛋白α重链百分比和肌原纤维ATPase活性升高,β重链百分比降低(p<0.05)。与此变化相反,自发性高血压大鼠和由异丙肾上腺素诱导的心肌肥大大鼠心室肌球蛋α重链百分比和肌纤维ATPase活性降低,β重链百分比升高(P<0.05)。说明运动心脏的重塑过程不同于病理性心脏,前者重塑后使心肌收缩性提高,后者重塑后心脏功能降低。 相似文献