Voultsios A, Kennaway D J, Dawson D
Department of Obstetrics and Gynaecology, University of Adelaide Medical School, South Australia.
J Biol Rhythms. 1997 Oct;12(5):457-66. doi: 10.1177/074873049701200507.
There are many situations in which it would be useful to know the phase state of the biological clock. It is recognized that measurement of melatonin levels can provide this information, but traditionally blood has been used for the analysis, and there are many problems in extending the measurements into the home or field situations. The aim of this study was to develop and validate a salivary melatonin radioimmunoassay and to compare results obtained against a plasma assay for determining the onset of melatonin secretion. The assay developed was sensitive (4.3 pM) and required only 200 microliters of sample. A rhythm in melatonin was detected in saliva, peaking at approximately 120 pM or 30% of the plasma levels. Using an objective criterion for determining the onset of secretion (mean +/- 2 standard deviations of three daytime samples), the time of onset was shown to exhibit low intraindividual variability (coefficient of variation = 1.5%-4.3%). The time of onset determined using saliva was significantly correlated with the plasma onset (r = .70, p < .05). The onsets determined were 22:30 h +/- 22 min for the saliva and 21:50 h +/- 16 min for plasma for 17 subjects. Similarly, the acrophases of the saliva and plasma melatonin rhythms were significantly correlated. Neither posture alone nor changes in posture affected the calculation of the onset of melatonin secretion using the saliva approach. Very high saliva flow rates induced by citric acid resulted in lower melatonin concentrations compared to the gentle chewing on parafin film. These results firmly establish the use of salivary melatonin measurements for phase typing of the melatonin rhythm in humans.
在许多情况下，了解生物钟的相位状态会很有用。人们认识到，测量褪黑素水平可以提供这一信息，但传统上一直使用血液进行分析，而将测量扩展到家庭或野外环境存在许多问题。本研究的目的是开发并验证一种唾液褪黑素放射免疫测定法，并将其结果与血浆测定法进行比较，以确定褪黑素分泌的开始时间。所开发的测定法灵敏度高（4.3皮摩尔），仅需200微升样品。在唾液中检测到褪黑素节律，峰值约为120皮摩尔或血浆水平的30%。使用客观标准确定分泌开始时间（三个白天样本的平均值±2个标准差），结果显示开始时间的个体内变异性较低（变异系数=1.5%-4.3%）。使用唾液确定的开始时间与血浆开始时间显著相关（r = 0.70，p < 0.05）。17名受试者唾液的开始时间为22:30 h±22分钟，血浆的开始时间为21:50 h±16分钟。同样，唾液和血浆褪黑素节律的高峰相位也显著相关。单独的姿势或姿势变化均不影响使用唾液法计算褪黑素分泌的开始时间。与轻轻咀嚼石蜡膜相比，柠檬酸诱导的非常高的唾液流速导致褪黑素浓度较低。这些结果牢固地确立了使用唾液褪黑素测量来对人类褪黑素节律进行相位分型。
