The parathyroid hormone circadian rhythm is truly endogenous - A general clinical research center study
The parathyroid hormone circadian rhythm is truly endogenous - A general clinical research center study
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DOI：
10.1210/jc.82.1.281
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发表时间：
1997-01-01
影响因子：
5.8
通讯作者：
Czeisler, CA
中科院分区：
文献类型：
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作者：
El-Hajj Fuleihan, G;Klerman, EB;Czeisler, CA
虽然甲状旁腺激素的循环水平遵循昼夜模式，但尚不清楚这些变化是真正的内源性还是由外部因素决定的，这些外部因素本身遵循昼夜模式，如睡眠-觉醒周期、光-暗周期、饮食或姿势。我们在我们的强化生理监测单元评估了11名正常健康男性志愿者甲状旁腺激素的日节律。在基线条件下度过的前36小时，随后是28-40小时的恒定常规条件（CR；严格的半卧位强制清醒，每小时吃零食）。在基线条件下，PTH水平遵循双峰昼夜节律，平均振幅为4.2 pg/mL。初峰（t(1max)）出现在0314 h，次峰（t(2max)）出现在1726 h，而初峰和次峰（t(1min)）平均分别出现在1041和2103 h。这种节律在CR条件下得以保留，尽管具有不同的特征，从而证实了其内源性。血清离子钙（Ca-i）在研究的5名受试者中有3名显示出节律，个体之间差异很大，与甲状旁腺激素没有任何明显的关系。在基线日，尿钙/肌酐（UCa/Cr）、磷酸/铬（UPO4/Cr）和钠/铬（UNa/Cr）比值均遵循昼夜节律。这些节律在CR期间持续存在，尽管前两个参数具有不同的特征，而UNa/ CR不变。总的来说，UCa/Cr曲线的时间模式是PTH曲线的镜像，而UPO4/Cr模式与PTH曲线平行移动。总之，甲状旁腺激素水平在CR期间表现出持续的昼夜节律，从而证实这种节律的很大一部分是内源性昼夜节律。这种节律的临床相关性反映在PTH在肾脏作用的生物标志物的相关节律上，即UCa/Cr和UPO4/Cr。
While circulating levels of PTH follow a diurnal pattern, it has been unclear whether these changes are truly endogenous or are dictated by external factors that themselves follow a diurnal pattern, such as sleep-wake cycles, light-dark cycles, meals, or posture.We evaluated the diurnal rhythm of PTH in 11 normal healthy male volunteers in our Intensive Physiologic Monitoring Unit. The first 36 h spent under baseline conditions were followed by 28-40 h of constant routine conditions (CR; enforced wakefulness in the strict semirecumbent position, with the consumption of hourly snacks). During baseline conditions, PTH levels followed a bimodal diurnal rhythm with an average amplitude of 4.2 pg/mL. A primary peak (t(1max)) occurred at 0314 h, and the secondary peak (t(2max)) occurred at 1726 h, whereas the primary and secondary nadirs (t(1min) and t(2min)) took place, on the average, at 1041 and 2103 h, respectively. This rhythm was preserved under CR conditions, albeit with different characteristics, thus confirming its endogenous nature. The serum ionized calcium (Ca-i) demonstrated a rhythm in 3 of the 5 subjects studied that varied widely between individuals and did not have any apparent relation to PTH. Urinary calcium/creatinine (UCa/Cr), phosphate/Cr (UPO4/Cr), and sodium/Cr (UNa/Cr) ratios all followed a diurnal rhythm during the baseline day. These rhythms persisted during the CR, although with different characteristics for the first two parameters, whereas that of UNa/Cr was unchanged. In general, the temporal pattern for the UCa/Cr curve was a mirror image of the PTH curve, whereas the UPO4/Cr pattern moved in parallel with the PTH curve.In conclusion, PTH levels exhibit a diurnal rhythm that persists during a CR, thereby confirming that a large component of this rhythm is an endogenous circadian rhythm. The clinical relevance of this rhythm is reflected in the associated rhythms of biological markers of PTH effect at the kidney, namely UCa/Cr and UPO4/Cr.