Document Detail

Geomagnetic activity influences the melatonin secretion at latitude 70 degrees N.
MedLine Citation:
PMID:  11774869     Owner:  NLM     Status:  MEDLINE    
Factors other than light may affect variations in melatonin, including disturbances in the geomagnetic field. Such a possibility was tested in Alta, Norway, located at latitude 70 degrees N, where the aurora borealis is a result of large changes in the horizontal component (H) of the geomagnetic field. Geomagnetic disturbances are felt more strongly closer to the pole than at lower latitudes. Also noteworthy in Alta is the fact that the sun does not rise above the horizon for several weeks during the winter. To examine whether changes in geomagnetic activity influence the secretion of melatonin, saliva was collected from 25 healthy subjects in Alta several times during the day-night and at different times of the year. Single cosinor analyses yielded individual estimates of.the circadian amplitude and MESOR of melatonin. A 3-hour mean value for the local geomagnetic activity index, K, was used for approximately the same 24-hour span. A circadian rhythm was found to characterize both melatonin and K, the peak in K (23:24) preceding that of melatonin (06:08). During the span of investigation, a circannual variation also characterized both variables. Correlation analyses suggest that changes in geomagnetic activity had to be of a certain magnitude to affect the circadian amplitude of melatonin. If large enough (> 80 nT/3 h), changes in geomagnetic activity also significantly decreased salivary melatonin concentration.
A Weydahl; R B Sothern; G Cornélissen; L Wetterberg
Related Documents :
2555249 - Melatonin reduction by lithium and albinism in quail and hamsters.
9742299 - Melatonin: the dark force.
16687299 - High-intensity red light suppresses melatonin.
6792319 - The anovulatory hamster: a comparison of the effects of short photoperiod and daily mel...
2133129 - Phase shifts in the circadian rhythm in plasma concentrations of melatonin in rams indu...
18502399 - Intraocular microinjections repair experimental parkinson's disease.
10212419 - Frequency glides in the impulse responses of auditory-nerve fibers.
21368149 - Drought variability in the pacific northwest from a 6,000-yr lake sediment record.
32619 - Intraventricular carbachol mimics the effects of light on the circadian rhythm in the r...
Publication Detail:
Type:  Clinical Trial; Journal Article    
Journal Detail:
Title:  Biomedicine & pharmacotherapy = Biomédecine & pharmacothérapie     Volume:  55 Suppl 1     ISSN:  0753-3322     ISO Abbreviation:  Biomed. Pharmacother.     Publication Date:  2001  
Date Detail:
Created Date:  2001-12-31     Completed Date:  2002-06-12     Revised Date:  2004-11-17    
Medline Journal Info:
Nlm Unique ID:  8213295     Medline TA:  Biomed Pharmacother     Country:  France    
Other Details:
Languages:  eng     Pagination:  57s-62s     Citation Subset:  IM    
Finnmark University College, Alta, Norway.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Arctic Regions
Circadian Rhythm
Electromagnetic Fields*
Melatonin / metabolism*
Saliva / metabolism
Reg. No./Substance:

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Geomagnetic disturbance associated with decrease in heart rate variability in a subarctic area.
Next Document:  Alternating light-darkness-influenced human electrocardiographic magnetoreception in association wit...