Sleep shift dissociates the nocturnal peaks of parathyroid hormone (1-84), nephrogenous cyclic adenosine monophosphate, and prolactin in normal men.
The secretion of PTH(1-84) and PRL over a 24-h period in normal subjects has been shown to be highly correlated, with changes in PRL occurring approximately 2 h after those in PTH(1-84). It has been postulated that there may be neuroendocrine control common to PTH(1-84) and PRL. As the secretion of PRL is known to be strongly influenced by sleep we investigated the effect of a 7-h acute sleep shift on the nocturnal secretion of PTH(1-84), PRL, and nephrogenous cAMP, a marker of PTH(1-84) bioactivity. Six normal male subjects were studied on two occasions (study A sleep, 0100-0800 h; study B, 0800-1400 h) with samples withdrawn at 30-min intervals. Sleep shift produced the expected shift in PRL secretion to new time of sleep. The overall timing of the PTH(1-84) nocturnal peak (0200-0600 h) was not altered by sleep shift. However, the start of the rise in PTH(1-84) (0200-0300 h) was blunted (P less than 0.05), and the peak of nephrogenous cAMP, coincident with the nocturnal rise in PTH(1-84) in study A, was markedly attenuated (P less than 0.01). Thus whereas the results of this study argue against a direct neuroendocrine link between PTH(1-84) and PRL, it is postulated that sleep shift disrupts a high degree of temporal organization which, under normal conditions, may allow concerted metabolic effects between PTH(1-84) and other hormones over a 24-h period.
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Institute of Biochemistry, Royal Infirmary, Glasgow, Scotland.
Fraser
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WD
O'Reilly
D S
DS
Christie
J
J
Cameron
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DA
Wallace
D C
DC
Beastall
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GH
D000328:Adult; D002118:Calcium / Q000032:analysis; D002940:Circadian Rhythm; D000242:Cyclic AMP / Q000378:metabolism*; D006801:Humans; D007668:Kidney / Q000378:metabolism; D008297:Male; D010281:Parathyroid Hormone / Q000378:metabolism*; D011388:Prolactin / Q000378:metabolism*; D012890:Sleep / Q000502:physiology*
D010281:Parathyroid Hormone; D011388:Prolactin; D000242:Cyclic AMP; D002118:Calcium