Posture influences melatonin concentrations in plasma and saliva in humans.

Author(s): Deacon S, Arendt J

Publication: Neurosci Lett, 1994, Vol. 167, Page 191-4

PubMed ID: 8177523 PubMed Review Paper? No

Purpose of Paper

Conclusion of Paper

Studies

1. Study Purpose

   The purpose of this study was to determine the effects of patient posture and time of biospecimen collection on the levels of melatonin in plasma and saliva from 7 volunteers. Plasma and saliva melatonin levels were also compared. Individuals remained seated between 9 pm and 12 am, at which point they switched positions between standing and supine for 30 min intervals, or remained standing or supine for a single 90 min interval. Plasma and saliva specimens were stored at -20 degrees C until analysis.

   Summary of Findings:

   Levels of salivary and plasma melatonin increased when individuals changed from a sitting or supine position to standing in 30 min intervals. These changes in melatonin were more significant in plasma than in saliva. Plasma melatonin increased with time in specimens collected while individuals remained supine or standing for 90 min, however, the increase was greater in specimens taken from standing individuals. The authors state that variable changes in salivary melatonin levels over a 90 min interval between standing and supine collections were insignificant. Salivary levels of serotonin showed good correlation with plasma levels and were approximately 46.2% and 40.4% as high as plasma levels during hourly and 10 minute sampling, respectively. The authors note that the lower significance and higher variability of melatonin levels in saliva may be related to the high frequency of forced saliva sampling (every 10 min).

   Biospecimens

   • Bodily Fluid - Plasma
   • Bodily Fluid - Saliva
   • Bodily Fluid - Blood

   Preservative Types

   • Frozen

   Diagnoses:

   • Normal

   Platform:

   Analyte	Technology Platform
   Small molecule	Radioimmunoassay

   Pre-analytical Factors:

   Classification	Pre-analytical Factor	Value(s)
   Biospecimen Acquisition	Time of biospecimen collection	12 am 12:10 am 12:20 am 12:30 am 12:40 am 12:50 am 1 am 1:10 am 1:20 am 1:30 am 9 pm 10 pm 11 pm
   Biospecimen Acquisition	Biospecimen location	Plasma Saliva
   Biospecimen Acquisition	Patient posture	Sitting Standing Supine

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