文章基本信息

标题：Different Behavior of Forearm Blood Flow during Intermittent Isometric Handgrip in a Thermo-neutral and a Hot Environment
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作者：Chang-franw Lee ; Tetsuo Katsuura ; Hajime Harada 等
期刊名称：Journal of PHYSIOLOGICAL ANTHROPOLOGY and Applied Human Science
印刷版ISSN：1345-3475
出版年度：1995
卷号：14
期号：3
页码：111-117
DOI：10.2114/ahs.14.111
出版社：Japan Society of Physiological Anthropology
摘要：The purpose of the present study was to evaluate the different behavior of forearm blood flow (FBF) during intermittent isometric handgrip (IIHG, 6 seconds contraction +6 seconds relaxation) in a thermo-neutral versus a hot environment. Six healthy men performed three times of 5-minute period IIHG at three different work loads (10%, 20% and 30% MVC). The IIHG was performed with the right hand. The experiments of IIHG were performed at two different air temperatures (25°C and 40°C, RH: 50%), and an experiment without work was also carried out at 40°C (RH: 50%). The physiological responses measured involved heart rate (HR), cardiac output (CO), mean arterial blood pressure (MBP), FBF, and skin blood flow (SBF). HR, CO and SBF showed higher values during IIHG at 40°C than at 25°C. MBP had a tendency to increase with the intensity of work load at both 25°C and 40°C. Since intramuscular pressure might increase during contraction periods at 20% MVC and 30% MVC at 25'C, FBF was significantly higher during relaxation periods than during contraction periods. FBF showed similar values between contraction and relaxation periods at lO% MVC at both temperatures. The present study suggested that FBF was sufficient for active muscles during IIHG at 10% MVC. FBF of contraction periods was close to that of relaxation periods at 40'C due to the modulation of the sympathetic outflow to the muscles and/or the decreased efficiency of the muscle pump. It was suggested that FBF showed different behaviors during IIHG at 25'C versus at 40°C.
关键词：forearm blood flow;intermittent isometric handgrip;heat load;intramuscular pressure;muscle sympathetic nerve activity