Williamson Jon W, Querry Ross, McColl Rodderick, Mathews Dana
Department of Health Care Sciences, University of Texas Southwestern Medical Center, Dallas, TX 75390-9082, USA.
Med Sci Sports Exerc. 2009 Mar;41(3):574-80. doi: 10.1249/MSS.0b013e31818b98c8.
Regional cerebral blood flow (rCBF) in the insular cortex (IC), a well-recognized site for central blood pressure (BP) modulation, is decreased at minute 10 during postexercise hypotension (PEH).
To determine whether exercise-induced decreases in IC rCBF are associated with BP changes throughout PEH.
Ten subjects were studied on three different days using a counterbalanced design with a randomized order for conditions; all were tested during a resting baseline and then at two of three time points postexercise: 10, 30, and 60 min. Data were collected for HR, mean BP, and rCBF using single-photon emission computed tomography as an index of brain activation.
Using ANOVA across conditions, there were differences (P < 0.05; mean +/- SD) for HR from baseline at minute 10 (+15 +/- 4 bpm) and minute 30 (+6 +/- 3 bpm) and for mean BP at minute 10 (-11 +/- 4 mm Hg) and minute 30 (-5 +/- 3 mm Hg). There were significant decreases (P < 0.05) in rCBF at both minutes 10 and 30 after exercise in the inferior thalamus and the right inferior IC regions. Although there were no decreases in BP or IC activity at minute 60, changes in right inferior posterior IC activity and BP were strongly correlated (r2 = 0.74; P < 0.05) postexercise.
Findings show that exercise-induced decreases in IC and thalamic activity may be a significant neural factor contributing to at least the first 30 min of PEH.
岛叶皮质（IC）是公认的中枢血压（BP）调节部位，运动后低血压（PEH）期间第10分钟时其局部脑血流量（rCBF）降低。
确定运动诱导的IC区rCBF降低是否与整个PEH过程中的血压变化相关。
10名受试者在三天内采用平衡设计，条件随机排序进行研究；所有人在静息基线期进行测试，然后在运动后的三个时间点中的两个时间点进行测试：10分钟、30分钟和60分钟。使用单光子发射计算机断层扫描收集心率、平均血压和rCBF数据，作为脑激活指标。
采用方差分析，与基线相比，第10分钟（+15±4次/分钟）和第30分钟（+6±3次/分钟）时心率有差异（P<0.05；平均值±标准差），第10分钟（-11±4mmHg）和第30分钟（-5±3mmHg）时平均血压有差异。运动后第10分钟和第30分钟，下丘脑下部和右侧岛叶皮质下部区域的rCBF显著降低（P<0.05）。虽然第60分钟时血压和岛叶皮质活动没有降低，但运动后右侧岛叶皮质后部下部活动与血压变化密切相关（r2=0.74；P<0.05）。
研究结果表明，运动诱导的岛叶皮质和丘脑活动降低可能是导致至少PEH前30分钟的一个重要神经因素。
