Responses of Hypothalamic-Pituitary-Adrenal axis to cold pressor stimulation

目的：已知下丘脑-垂体-肾上腺（HPA）轴的功能异常与慢性疼痛病症（例如，纤维肌痛）。本研究观察了冷加压刺激对血浆内源性阿片、HPA激素及三叉神经热痛阈的影响。方法：在CP试验中，10名健康男性（平均年龄：25.3 ± 1.3岁）将右手浸入4℃冷水中2分钟。模拟试验也在没有冷水的情况下进行。分别于刺激前5 min、刺激中、刺激后5、15、30、45、60 min采集全血，测定促肾上腺皮质激素释放因子（CRF）、促肾上腺皮质激素（ACTH）、β-内啡肽（β-EP）和皮质醇（cortisol）。离心全血以分离血浆，然后冷冻（-20℃）用于后续测定。用放射免疫法测定血浆CRF、ACTH、β-内啡肽和皮质醇浓度。受试者右V2区的热痛阈值同时 ...更多信息 使用热感觉分析仪（Medoc，Israel）在CPS之前5分钟和之后5、30、60分钟记录。结果如下：平均血浆ACTH和β-内啡肽水平在CP刺激停止后5分钟显著增加，并在60分钟内恢复至基线（p<0.01，单因素重复测量ANOVA）。在停止CP刺激后30分钟，平均血浆皮质醇水平也增加（p<0.01），而血浆CRF没有检测到变化（p=0.83）。在实验时间过程中，平均热痛阈值没有显示出统计学显着变化（p=0.41），因为即使使用相同的CP刺激时间表，10名受试者中的4名也没有显示出热痛阈值的明显变化。同时，在本研究中没有观察到的变量显示在模拟试验中的显着变化。结论：这些结果表明，CP刺激诱导健康男性血浆内源性阿片和HPA激素水平的进行性增加，但这种急性血浆内源性阿片增加并不总是与V2皮肤区域的热痛阈值反应。少

Objective : Functional abnormalities of Hypothalamic-Pituitary-Adrenal (HPA) axis have been known implicated in chronic pain conditions (e.g., fibromyalgia). This study evaluated the changes in plasma endogenous opioid, HPA hormones concentration and trigeminal heat pain threshold upon cold pressor (CP) stimulation. Methods : In CP trials, ten healthy males (mean age : 25.3^^+__-1.3yrs) immersed their right hands for 2 minutes in 4℃ cold water. Mock trials were also done without the cold water. Whole blood samples were collected 5 minutes before, during, and 5, 15, 30, 45, 60 minutes after CP and mock stimulation for measuring Corticotropin-Releasing-Factor (CRF), Adrenocorticotropic hormone (ACTH), β-endorphine and cortisol. Whole blood was centrifuged for plasma separation, then frozen (-20℃) for later assay. Plasma CRF, ACTH, β-endorphine and cortisol concentrations were determined using radioimmunoassay techniques. Heat pain thresholds in subjects' right V2 region were simultaneous … More ly recorded 5 minutes before and 5, 30, 60 minutes after CPS using Thermal Sensory Analyzer (Medoc, Israel). Results : Mean plasma ACTH and β-endorphine levels significantly increased 5 minutes after cessation of CP stimulation and returned to the baseline in 60 minutes (p<0.01, One-way repeated measure ANOVA). Mean plasma cortisol levels also increased 30 minutes after cessation of CP stimulation (p<0.01), while no plasma CRF change was detectable (p=0.83). Mean heat pain thresholds did not show statistically significant changes during the experimental time course (p=0.41), since 4 of 10 subjects showed no obvious change in the heat pain thresholds even with the same CP stimulation schedule. Meanwhile, no variables observed in this study showed a significant change in the mock trial. Conclusions : These results suggest that CP stimulation induces progressive increase in plasma endogenous opioid and HPA hormones levels in healthy males, but this acute plasma endogenous opioid increase does not always associate to heat pain threshold responses in V2 skin region. Less