Inder W J, Hellemans J, Ellis M J, Evans M J, Livesey J H, Donald R A
Department of Endocrinology, Christchurch Hospital, New Zealand.
J Clin Endocrinol Metab. 1995 Jan;80(1):244-8. doi: 10.1210/jcem.80.1.7829620.
Basal cortisol and ACTH levels have previously been shown to be elevated in highly trained athletes, whereas the ACTH response to ovine CRH has been reported to be diminished compared to that in nonathletic controls. Naloxone, a nonselective opioid receptor antagonist, is known to stimulate ACTH and cortisol secretion. The mechanism of this response is thought to be via increased hypothalamic CRH secretion. The aim of this study was to examine basal and naloxone-stimulated levels of hypothalamic-pituitary-adrenal axis hormones in male athletes. Ten highly trained male athletes and 10 nonathletic controls took part in the study. Peripheral venous blood was sampled for cortisol, ACTH, CRH, and arginine vasopressin (AVP) for 2 h before the administration of 20 mg naloxone, i.v., and 15, 30, 45, 60, 90, and 120 min after naloxone treatment. Body mass index was significantly lower in the athletes (P < 0.001). Basal (prenaloxone) ACTH levels were higher in the athletes (P < 0.05), whereas levels of cortisol, CRH, and AVP were similar in both groups. After naloxone treatment, there was a significantly greater rise in ACTH in the athletes (P < 0.02). There was also a trend for the cortisol response to be greater, which was not statistically significant (P < 0.07). Although in both groups, peripheral CRH rose after naloxone treatment (P < 0.005), a rise of similar magnitude occurred over the 2-h period before naloxone (P < 0.0001). Plasma AVP did not change significantly after naloxone treatment. Neither the plasma cortisol level at baseline nor the body mass index correlated significantly with the ACTH or cortisol response to naloxone. The presence of an enhanced ACTH response to naloxone is evidence that central opioid tone may be increased in highly trained athletes. However, there is no associated suppression of the hypothalamic-pituitary-adrenal axis, and basal ACTH levels are raised, without any detectable change in peripheral plasma CRH or AVP. An additional factor (other than CRH) that stimulates ACTH secretion may be released after naloxone administration.
先前的研究表明，高水平训练的运动员基础皮质醇和促肾上腺皮质激素（ACTH）水平会升高，而与非运动员对照组相比，据报道运动员对羊促肾上腺皮质激素释放激素（CRH）的ACTH反应会减弱。纳洛酮是一种非选择性阿片受体拮抗剂，已知它能刺激ACTH和皮质醇分泌。这种反应的机制被认为是通过增加下丘脑CRH分泌来实现的。本研究的目的是检测男性运动员下丘脑-垂体-肾上腺轴激素的基础水平和纳洛酮刺激后的水平。10名高水平训练的男性运动员和10名非运动员对照组参与了该研究。在静脉注射20毫克纳洛酮前2小时以及纳洛酮治疗后15、30、45、60、90和120分钟采集外周静脉血，检测皮质醇、ACTH、CRH和精氨酸加压素（AVP）。运动员的体重指数显著更低（P<0.001）。运动员的基础（纳洛酮给药前）ACTH水平更高（P<0.05），而两组的皮质醇、CRH和AVP水平相似。纳洛酮治疗后，运动员的ACTH升高幅度显著更大（P<0.02）。皮质醇反应也有更大的趋势，但无统计学意义（P<0.07）。虽然两组中纳洛酮治疗后外周CRH均升高（P<0.005），但在纳洛酮给药前的2小时内也出现了类似幅度的升高（P<0.0001）。纳洛酮治疗后血浆AVP无显著变化。基线血浆皮质醇水平和体重指数均与对纳洛酮的ACTH或皮质醇反应无显著相关性。对纳洛酮的ACTH反应增强表明，高水平训练的运动员中枢阿片类物质张力可能增加。然而，下丘脑-垂体-肾上腺轴没有相关抑制，基础ACTH水平升高，外周血浆CRH或AVP没有任何可检测到的变化。纳洛酮给药后可能会释放另一种刺激ACTH分泌的因素（除CRH外）。
