Nair N P, Hariharasubramanian N, Pilapil C, Isaac I, Thavundayil J X
Biol Psychiatry. 1986 Feb;21(2):141-50. doi: 10.1016/0006-3223(86)90141-1.
We investigated the age-related changes in the circadian rhythm of plasma melatonin as a potential index of brain aging in man. The subjects were 5 young men aged 19-25 years, 11 older men aged 51-65 years, 6 elderly men aged 66-89 years, 7 young women aged 19-25 years, 5 premenopausal women aged 45-50 years, 8 postmenopausal women aged 51-65 years, and 5 elderly women aged 66-75 years. They were all physically and psychiatrically normal. Serial blood samples were drawn from 8:00 AM until 8:00 AM on the next day, with the indoor illumination set at 300 Lux from 7:00 AM until 4:00 PM and at 50 Lux thereafter. Plasma melatonin was estimated by radioimmunoassay. The results show that there is a significant negative correlation between age and 24-hr secretion of plasma melatonin (r = -0.952, p less than 0.0001), between age and peak levels of plasma melatonin (r = -0.937, p less than 0.00001), and between age and the lag in time from sunset to the onset of significant elevation of plasma melatonin over daytime values (r = 0.916, p less than 0.0001). It is concluded that study of the circadian rhythm of plasma melatonin may prove to be a useful index of the aging process.
我们研究了血浆褪黑素昼夜节律的年龄相关变化，将其作为人类大脑衰老的一个潜在指标。受试者包括5名年龄在19 - 25岁的年轻男性、11名年龄在51 - 65岁的老年男性、6名年龄在66 - 89岁的高龄男性、7名年龄在19 - 25岁的年轻女性、5名年龄在45 - 50岁的绝经前女性、8名年龄在51 - 65岁的绝经后女性以及5名年龄在66 - 75岁的老年女性。他们在身体和精神方面均正常。从上午8点至次日上午8点采集系列血样，上午7点至下午4点室内光照设置为300勒克斯，此后为50勒克斯。采用放射免疫分析法测定血浆褪黑素。结果显示，年龄与血浆褪黑素24小时分泌量之间存在显著负相关（r = -0.952，p < 0.0001），年龄与血浆褪黑素峰值水平之间存在显著负相关（r = -0.937，p < 0.00001），年龄与从日落到血浆褪黑素显著升高超过白天值的时间滞后之间存在显著正相关（r = 0.916，p < 0.0001）。结论是，对血浆褪黑素昼夜节律的研究可能被证明是衰老过程的一个有用指标。
