Gillis D Jason, Weston Neil, House James R, Tipton Michael J
Extreme Environments Laboratory, Department of Sport and Exercise Science, The University of Portsmouth, UK.
Extreme Environments Laboratory, Department of Sport and Exercise Science, The University of Portsmouth, UK.
Physiol Behav. 2015 Feb;139:511-8. doi: 10.1016/j.physbeh.2014.12.009. Epub 2014 Dec 5.
A single exposure to menthol can, depending on concentration, enhance both cool sensations and encourage body heat storage. This study tested whether there is an habituation in either response after repeated-daily exposures. Twenty-two participants were assigned to one of three spray groups: Control (CON; n=6), 0.05% L-menthol (M(0.05%); n=8), and 0.2% L-menthol (M(0.2%); n=8). On Monday (20°C, 50% rh) participants were sprayed with 100 mL of solution and undertook 40 min of cycling at 45% of their peak power (Ex1), from Tuesday to Thursday (30°C, 50% rh) they were sprayed twice daily whilst resting (R1 to R6), Friday was a repeat of Monday (Ex2). Thermal sensation (TS), thermal comfort, perceived exertion, irritation, rectal and skin temperature (Tsk), skin blood flow (SkBF) and sweat rate were monitored. A two-way ANOVA (alpha=0.05) compared responses from the beginning (Ex1, R1) and end (Ex2, R5) of the testing week. M(0.2%) induced significantly (P<0.05) cooler TS at the beginning of the week (Ex1, R1) compared to the end (Ex2, R5), indicating habituation of TS; this was not observed in M(0.05%). No other perceptual or physiological responses habituated. 0.2% Menthol caused a heat storage response, mediated by vasoconstriction, at the beginning and end of the week, suggesting the habituation of TS occurred in a pathway specific to sensation. In summary, the cooling influence of 0.2% menthol habituates after repeated-daily exposures, but with no habituation in heat storage.
单次接触薄荷醇，根据浓度不同，既能增强冷感，又会促进身体热量储存。本研究测试了在每天重复接触后，这两种反应是否会出现适应性变化。22名参与者被分配到三个喷雾组之一：对照组（CON；n = 6）、0.05% L - 薄荷醇组（M(0.05%)；n = 8）和0.2% L - 薄荷醇组（M(0.2%)；n = 8）。周一（20°C，相对湿度50%），给参与者喷洒100 mL溶液，并以其峰值功率的45%进行40分钟的骑行（Ex1），从周二到周四（30°C，相对湿度50%），他们在休息时每天喷洒两次（R1至R6），周五重复周一的操作（Ex2）。监测热感觉（TS）、热舒适度、主观用力程度、刺激感、直肠温度和皮肤温度（Tsk）、皮肤血流量（SkBF）以及出汗率。采用双向方差分析（α = 0.05）比较测试周开始（Ex1，R1）和结束（Ex2，R5）时的反应。与结束时（Ex2，R5）相比，M(0.2%)在本周开始时（Ex1，R1）诱导出显著更低的TS（P < 0.05），表明TS出现了适应性变化；而在M(0.05%)组未观察到这种情况。没有其他感知或生理反应出现适应性变化。0.2%的薄荷醇在本周开始和结束时均引起了由血管收缩介导的热量储存反应，这表明TS的适应性变化发生在特定的感觉通路中。总之，每天重复接触后，0.2%薄荷醇的降温影响会出现适应性变化，但热量储存方面没有适应性变化。
