Gerra G, Zaimovic A, Mascetti G G, Gardini S, Zambelli U, Timpano M, Raggi M A, Brambilla F
Addiction Research Center, Centro Studi Farmacotossicodipendenze, Ser. T., A.U.S.L., Via Spalato 2, 43100, Parma, Italy.
Psychoneuroendocrinology. 2001 Jan;26(1):91-107. doi: 10.1016/s0306-4530(00)00046-9.
Previous studies of hormonal and neurophysiological changes in response to psychological stress in humans have produced contrasting findings due to differing experimental procedures and consistent individual variability. Habituation effects, which influence physiological coping in response to exposure to repeated stress, need to be investigated more extensively. In the present study, twenty healthy male subjects were each exposed twice to the same psychosocial stressor (Stroop Color Word Interference task, public speaking and mental arithmetic in front of an audience) during a first session (day 1) and a second session (day 8). Plasma concentrations of norepinephrine (NE), epinephrine (EPI), adrenocorticotropic hormone (ACTH), cortisol (CORT) and prolactin (PRL) were measured immediately before the beginning of the tests and at their end, 30 min later, on both experimental days. For the total group, NE, EPI, ACTH, and CORT levels were significantly elevated, and PRL levels were significantly decreased, after stress exposure on day 1. ACTH and CORT levels showed less significant increases after stress on day 8. In contrast, NE and EPI responses to stress were not significantly blunted, and PRL response was unchanged on day 8. Cluster analysis revealed two groups of subjects who showed different habituation patterns for ACTH and CORT. The first group (n=12) of subjects showed a reduction of ACTH and CORT responses to stress on day 8. The subjects of the second group (n=8) displayed a significant increase of ACTH and cortisol in response to stress on day 8, without any habituation effect. These results increase the evidence concerning the involvement of the HPA axis and catecholamines in response to psychological stress, and suggest that possible individual differences in the neuroendocrine coping mechanisms may affect mood regulation and the state of health.
先前关于人类对心理压力产生的激素和神经生理变化的研究，由于实验程序不同以及个体差异始终存在，得出了相互矛盾的结果。习惯化效应会影响对反复暴露于压力的生理应对，需要更广泛地进行研究。在本研究中，20名健康男性受试者在第一次实验（第1天）和第二次实验（第8天）期间，均两次暴露于相同的心理社会应激源（斯特鲁普颜色词干扰任务、公开演讲以及在观众面前进行心算）。在两个实验日中，分别于测试开始前及结束后30分钟测量血浆去甲肾上腺素（NE）、肾上腺素（EPI）、促肾上腺皮质激素（ACTH）、皮质醇（CORT）和催乳素（PRL）的浓度。对于整个实验组而言，在第1天应激暴露后，NE、EPI、ACTH和CORT水平显著升高，PRL水平显著降低。在第8天应激后，ACTH和CORT水平的升高不太显著。相比之下，NE和EPI对应激的反应在第8天并未显著减弱，PRL反应也未改变。聚类分析揭示了两组受试者，他们对ACTH和CORT表现出不同的习惯化模式。第一组（n = 12）受试者在第8天对应激的ACTH和CORT反应有所降低。第二组（n = 8）受试者在第8天对应激的ACTH和皮质醇显著增加，没有任何习惯化效应。这些结果增加了关于HPA轴和儿茶酚胺参与心理应激反应的证据，并表明神经内分泌应对机制中可能存在的个体差异可能会影响情绪调节和健康状况。
