Ferrari E, Magri F, Locatelli M, Balza G, Nescis T, Battegazzore C, Cuzzoni G, Fioravanti M, Solerte S B
Department of Internal Medicine and Medical Therapy, University of Pavia, Italy.
Aging (Milano). 1996 Oct;8(5):320-7. doi: 10.1007/BF03339588.
The study of the neuroendocrine changes occurring in aging may give information about the CNS functions, and also explain the impaired plasticity of the aged organism. In 16 elderly women and in 14 young controls, the circadian rhythms of plasma melatonin, GH, PRL, ACTH and cortisol, and of oral temperature were simultaneously studied. The plasma cortisol circadian rhythm was also evaluated after DXM administration (1 mg orally at 23:00). The circadian profile of all the bioperiodic functions evaluated was clearly flattened in elderly subjects, and an impairment of the hormonal nocturnal secretion of GH, PRL and melatonin was apparent in elderly subjects when compared to young controls. The plasma ACTH levels throughout the 24-hour cycle were significantly higher in elderly than in young subjects. The cortisol circadian profile exhibited significantly higher values in the evening- and night-time in elderly subjects, compared to young controls; the cortisol nadir values were significantly age-related. A reduction of the sensitivity to DXM inhibition occurred in the elderly group. Both the selective impairment of nocturnal melatonin secretion, and the reduction of hypothalamo-pituitary-adrenal (HPA) sensitivity to steroid feed-back might be considered as markers of aging brain. The neuroendocrine alterations of physiological aging may be ascribable to both the structural and neurochemical changes occurring in the CNS.
对衰老过程中发生的神经内分泌变化进行研究，可能会提供有关中枢神经系统功能的信息，还能解释衰老机体可塑性受损的原因。对16名老年女性和14名年轻对照者同时研究了血浆褪黑素、生长激素（GH）、催乳素（PRL）、促肾上腺皮质激素（ACTH）和皮质醇的昼夜节律以及口腔温度。在给予地塞米松（DXM，23:00口服1毫克）后，还评估了血浆皮质醇的昼夜节律。在老年受试者中，所有评估的生物周期功能的昼夜模式明显变平，与年轻对照者相比，老年受试者中GH、PRL和褪黑素的夜间激素分泌明显受损。老年受试者在整个24小时周期内的血浆ACTH水平显著高于年轻受试者。与年轻对照者相比，老年受试者的皮质醇昼夜模式在傍晚和夜间表现出显著更高的值；皮质醇最低点值与年龄显著相关。老年组对地塞米松抑制的敏感性降低。夜间褪黑素分泌的选择性受损以及下丘脑-垂体-肾上腺（HPA）对类固醇反馈的敏感性降低，都可能被视为衰老大脑的标志。生理性衰老的神经内分泌改变可能归因于中枢神经系统发生的结构和神经化学变化。
