Watkins Austen M, Cheek Dennis J, Harvey Alison E, Goodwin John D, Blair Kara E, Mitchell Joel B
Department of Kinesiology, Texas Christian University, Fort Worth, TX 76129, USA.
Aviat Space Environ Med. 2007 Sep;78(9):901-5.
Acute bouts of heat stress and exercise have been shown to independently increase heat shock protein levels; however, the combination of these two stressors on HSP-72 expression in human skeletal muscle has not been established. The purpose of this study was to determine the effect of a bout of exercise in the heat on HSP-72 expression.
There were eight recreationally active men (Age = 26.4 +/- 3.1 yr, V(O2)peak = 4.01 +/- 0.25 L min(- 1)) who completed two 30-min bouts of cycle ergometry at 75% of V(O2)peak in a hot (39 degrees C; RH 30%) and cold (9 degrees C; RH 61%) environment. Muscle biopsies were obtained from the vastus lateralis prior to, 6 h post, and 24 h post-exercise to measure HSP-72 protein. Core rectal temperature (Tc), average skin temperature (T(SK)), intramuscular temperature (T(IM)), heart rate (HR), oxygen uptake (V(O2)), sweat rate (SR), and plasma cortisol were measured to determine thermal loads.
No significant interactions were present between V(O2) (2.80 +/- 0.2 vs. 2.65 +/- 0.1 L min(-1)) or plasma cortisol (27.1 +/- 2 vs. 19.2 +/- 4 microg dl(-1)) when comparing HT and CD. HR (184 +/- 5 vs. 159 +/- 7 bpm), T(IM) (40.7 +/- 0.2 vs. 40.0 +/- 0.2 degrees C), Tc (38.3 +/- 0.2 vs. 37.9 +/- 0.1 degrees C), T(SK) (36.7 +/- 0.2 vs. 29.6 +/- 0.8 degrees C), and SR (2.0 +/- 0.2 vs. 1.2 +/- 0.2 L h(-1)) were significantly greater when comparing HT and CD. HSP-72 was not altered as a result of either treatment (4.04 +/- 0.87 vs. 2.91 +/- 1.58 ng microg(-1) protein for HT and CD at 6 h post-exercise).
Exercise in the heat produced a greater thermal load than exercise in the cold; however, no significant increases in HSP-72 were seen when comparing hot and cold conditions.
急性热应激和运动已被证明可独立提高热休克蛋白水平；然而，这两种应激源对人类骨骼肌中HSP - 72表达的联合作用尚未明确。本研究的目的是确定在热环境中进行一轮运动对HSP - 72表达的影响。
八名有休闲运动习惯的男性（年龄 = 26.4 ± 3.1岁，峰值摄氧量 = 4.01 ± 0.25 L·min⁻¹）在炎热（39℃；相对湿度30%）和寒冷（9℃；相对湿度61%）环境中，以峰值摄氧量的75%完成了两轮30分钟的蹬车运动测试。在运动前、运动后6小时和24小时从股外侧肌获取肌肉活检样本，以测量HSP - 72蛋白。测量直肠核心温度（Tc）、平均皮肤温度（T(SK)）、肌肉内温度（T(IM)）、心率（HR）、摄氧量（V(O2)）、出汗率（SR）和血浆皮质醇，以确定热负荷。
比较热环境（HT）和冷环境（CD）时，V(O2)（2.80 ± 0.2 vs. 2.65 ± 0.1 L·min⁻¹）或血浆皮质醇（27.1 ± 2 vs. 19.2 ± 4 μg·dl⁻¹）之间不存在显著交互作用。比较HT和CD时，HR（184 ± 5 vs. 159 ± 7次/分钟）、T(IM)（40.7 ± 0.2 vs. 40.0 ± 0.2℃）、Tc（38.3 ± 0.2 vs. 37.9 ± 0.1℃）、T(SK)（36.7 ± 0.2 vs. 29.6 ± 0.8℃）和SR（2.0 ± 0.2 vs. 1.2 ± 0.2 L·h⁻¹）显著更高。两种处理后HSP - 72均未改变（运动后6小时，HT组为4.04 ± 0.87 ng·μg⁻¹蛋白，CD组为2.91 ± 1.58 ng·μg⁻¹蛋白）。
在热环境中运动比在冷环境中运动产生更大的热负荷；然而，比较热环境和冷环境时，未观察到HSP - 72有显著增加。
