γ-氨基丁酸对高温环境人体运动中体温调节的影响

Effects of Gamma-aminobutyric Acid on Body Temperature Regulation in Human during Exercise in a High-temperature Environment

目的:评价高温环境(31.5℃,55%相对湿度)γ-氨基丁酸(GABA)对人体运动中体温调节的影响。方法:2种条件,18名男性耐力性运动员以60%最大负荷进行40min功率自行车运动,60转/min。GABA运动实验(trial-G)口服运动饮料(3 ml/kg)含GABA 1 000 mg,对照运动实验(trial-C)口服等量运动饮料。连续测定核心体温(直肠温)、皮肤温。结果:trial-G中,核心体温在运动后12 min至运动结束低于trial-C,在运动后高于trial-C(均P<0.01)。trial-G中,平均皮肤温度在口服GABA 5 min后的安静期、运动中及恢复期均高于trial-C(均P<0.01)。trialG与trial-C运动结束时,核心体温为(38.45±0.25)℃与(36.58±0.42)℃(P<0.01),平均皮肤温度为(38.59±0.24)℃与(36.39±0.55)℃(P<0.01)。结论:高温环境口服GABA抑制人体运动中核心体温升高,促进皮肤散热,但运动后有严重高核心体温的危险。

Purpose： The purpose was to examine the effects of gamma-aminobutyric acid （ GABA ） on body temperature regulation in human during exercise in a high-temperature environment with 31.5℃ and 55% relative humidity. On two conditions ,eighteen trained male endurance athletes cycled at 60% maximal workload for 40 minutes on a cycle ergometer at a pedaling cadence of 60 map. In the GABA trial （trial-G） ,subjects drank sports drink （3ml/kg） containing GABA 1 000 mg, while subjects drank the same amount of sports drink in the control trial （trial-C）. During the experiments, core body temperature （rectum temperature） and skin temperatures were continuously measured. Results： Core body temperatures in the trial-G from the post-exercise at 12 minutes to the end of the exercise were significantly lower than those in the trial-C,in contrast core body temperatures in the recovery in the trial-G were significantly higher than those in the trial-C （ all P 〈0.01 ）. Mean skin temperatures in the trial-G after orally administrated GABA at 5 minutes during the rest,during the exercise period and the recovery, were all significantly higher than those in the trial-C （ all P 〈 0.01 ）. At the end point of the exercise in the trial-G and the trial-C, core body temperature were （ 38.45 ± 0.25 ） ℃ vs （ 36.58 ± 0.42） ℃（ P 〈 0. 01 ）, mean skin temperature were （ 38.59 ± 0.24 ）℃ vs （36.39 ± 0.55 ） ℃ P 〈 0.01 ）. Conclusions ： Oral administration of GABA in human during exercise in the high-temperature environment contributes to inhibit the increase in core body temperature and promote heat dissipation by skin. However, there exists a danger of serious hyperthermia post-exercise.