Coupling between the blood lactate-to-pyruvate ratio and MCA Vmean at the onset of exercise in humans
Coupling between the blood lactate-to-pyruvate ratio and MCA Vmean at the onset of exercise in humans
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DOI：
10.1152/japplphysiol.00468.2009
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发表时间：
2009-12-01
影响因子：
3.3
通讯作者：
Quistorff, Bjorn
中科院分区：
文献类型：
--
作者：
Rasmussen, Peter;Madsen, Camilla A.;Quistorff, Bjorn
Rasmussen P、Madsen CA、Nielsen HB、Zaar M、Gjedde A、Secher NH、Quistorff B。人类运动开始时血液乳酸与丙酮酸比率与 MCA V 平均值之间的耦合。 J Appl Physiol 107: 1799-1805, 2009。首次发表于 2009 年 9 月 24 日； doi:10.1152/japplphyol.00468.2009.-激活诱导的脑血流量增加与代谢活动增强相结合，可能以脑组织氧化还原状态和氧张力作为关键调节剂。为了评估人类运动开始时的这一假设，以 0.1 至 0.2 Hz 的频率从桡动脉和右颈内静脉采集血液样本，同时记录大脑中动脉平均流速（MCA V 平均值）。 10秒后，动脉和静脉乳酸丙酮酸比值均增加（P < 0.05），且动脉比值仍略高于静脉（P < 0.05）。计算得出的平均脑毛细血管氧张力在 5 秒后下降了 2.7 mmHg（P < 0.05），而 MCA V 平均值仅在 30 秒后才增加。此外，运动开始 50 秒后，大脑中碳水化合物的摄入量相对于氧气的摄入量而言变得显着。这些发现支持脑组织氧化还原状态和氧合作为运动开始时脑血流量增加的潜在调节剂。
Rasmussen P, Madsen CA, Nielsen HB, Zaar M, Gjedde A, Secher NH, Quistorff B. Coupling between the blood lactate-to-pyruvate ratio and MCA V-mean at the onset of exercise in humans. J Appl Physiol 107: 1799-1805, 2009. First published September 24, 2009; doi:10.1152/japplphysiol.00468.2009.-Activation-induced increase in cerebral blood flow is coupled to enhanced metabolic activity, maybe with brain tissue redox state and oxygen tension as key modulators. To evaluate this hypothesis at the onset of exercise in humans, blood was sampled at 0.1 to 0.2 Hz from the radial artery and right internal jugular vein, while middle cerebral artery mean flow velocity (MCA V-mean) was recorded. Both the arterial and venous lactate-to-pyruvate ratio increased after 10 s (P < 0.05), and the arterial ratio remained slightly higher than the venous (P < 0.05). The calculated average cerebral capillary oxygen tension decreased by 2.7 mmHg after 5 s (P < 0.05), while MCA V-mean increased only after 30 s. Furthermore, there was an unaccounted cerebral carbohydrate uptake relative to the uptake of oxygen that became significant 50 s after the onset of exercise. These findings support brain tissue redox state and oxygenation as potential modulators of an increase in cerebral blood flow at the onset of exercise.