Release of acetylcholine during whole‐body heating in aged skin
Release of acetylcholine during whole‐body heating in aged skin
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老化皮肤全身加热时乙酰胆碱的释放
DOI：
10.1096/fasebj.26.1_supplement.1084.5
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
C. Crandall
中科院分区：
文献类型：
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作者：
M. Shibasaki;H. Negishi;H. Kubo;K. Okazaki;C. Crandall
在老化皮肤中，全身热应力的出汗率（SR）减弱。这种衰减的可能机制是1）减少的神经信号传导，2）减弱的神经递质释放，和/或3）降低的汗腺对乙酰胆碱（ACh）的反应性。我们测试的假设，衰减释放乙酰胆碱在老化的皮肤可能有助于减少出汗在热应激。将皮内微透析探针置于8例青年（22±1岁）和7例老年（70±1岁）健康人前臂背侧和小腿皮肤。通过通气胶囊法在微透析膜上测量局部SR。通过每个膜灌注含有10 mM乙酰胆碱酯酶抑制剂新斯的明的林格氏溶液（灌注速率：2 μl/min），并以8 min为增量收集流出液。采用高压液相色谱-电化学检测器联用测定出水中的乙酰胆碱。全身加热使鼓膜温度升高约1.2°C。在整个热应激SR是较低的老年组，而释放的乙酰胆碱是相似的组之间在前臂和腿部网站。因此，老年组20 μl样品中SR/ACh比值显著低于老年组（前臂：0.10± 0.07vs0.21 ± 0.11mg/cm ~ 2/min/fmol，下肢：0.10± 0.06vs0.25 ± 0.13mg/cm ~ 2/min/fmol，均P<0.05）。这些结果表明，与年龄相关的SR减少不是由于ACh释放减弱。
Sweat rate (SR) to a whole‐body heat stress is attenuated in aged skin. Possible mechanisms of this attenuation are 1) reduced neural signaling, 2) attenuated release of neurotransmitter, and/or 3) decreased sweat gland responsiveness to acetylcholine (ACh). We tested the hypothesis that attenuated release of ACh in aged skin may contribute to decreases in sweating during a heat stress. Intradermal microdialysis probes were placed in dorsal forearm and lower leg skin in 8 young (22±1 yrs) and 7 old (70±1 yrs) healthy subjects. Local SR was measured over the microdialysis membranes by the ventilated capsule method. Ringerˈs solution containing 10mM of the acetylcholinesterase inhibitor neostigmine was perfused through each membrane (perfusion rate: 2 μl/min) and the effluent was collected at 8 min increments. ACh in the effluent was measured by high‐pressure liquid chromatography combined with electrochemical detector. Whole‐body heating increased tympanic temperature ~ 1.2°C. Throughout the heat stress SR was lower in the aged group, whereas the release of ACh was similar between groups at both forearm and leg sites. Therefore the SR/ACh ratio in the 20 μl sample was significantly lower in the aged group (Forearm: 0.10±0.07 vs 0.21±0.11 mg/cm2/min/fmol, Leg: 0.10±0.06 vs 0.25±0.13 mg/cm2/min/fmol, both P<0.05). These results suggest that the age‐related reduction in SR is not due attenuated release of ACh.