Coco Marinella, Alagona Giovanna, Rapisarda Giuseppe, Costanzo Erminio, Calogero Roberto Antonio, Perciavalle Valentina, Perciavalle Vincenzo
Department of Physiological Sciences, University of Catania, Catania, Italy.
Somatosens Mot Res. 2010;27(1):1-8. doi: 10.3109/08990220903471765.
No information has yet been provided about the influence of blood lactate levels on the excitability of the cerebral cortex, in particular, of the motor cortex. The aim of the present study was to examine the effects of high blood lactate levels, induced with a maximal cycling or with an intravenous infusion, on motor cortex excitability. The study was carried out on 17 male athletes; all the subjects performed a maximal cycling test on a mechanically braked cycloergometer, whereas 6 of them were submitted to the intravenous infusion of a lactate solution (3 mg/kg in 1 min). Before the exercise or the injection, at the end, as well as 5 and 10 min after the conclusion, venous blood lactate was measured and excitability of the motor cortex was evaluated by using the transcranial magnetic stimulation. In both of these experimental conditions, it was observed that an increase of blood lactate is associated with a decrease of motor threshold, that is, an enhancement of motor cortex excitability. We conclude by hypothesizing that in the motor cortex the lactate could have a protective role against fatigue.
关于血乳酸水平对大脑皮层，特别是运动皮层兴奋性的影响，目前尚未有相关信息。本研究的目的是检测通过最大强度骑行或静脉输注诱导的高血乳酸水平对运动皮层兴奋性的影响。该研究以17名男性运动员为对象；所有受试者均在机械制动的功率自行车上进行了最大强度骑行测试，其中6人接受了乳酸溶液的静脉输注（1分钟内输注3mg/kg）。在运动或注射前、结束时以及结束后5分钟和10分钟，测量静脉血乳酸，并通过经颅磁刺激评估运动皮层的兴奋性。在这两种实验条件下，均观察到血乳酸升高与运动阈值降低相关，即运动皮层兴奋性增强。我们通过假设得出结论，在运动皮层中，乳酸可能对疲劳具有保护作用。
