title: [Melatonin production in hypertonic patients during magnetic storms].
abstract: OBJECTIVE
  To study mechanisms of action of natural magnetic field of the Earth on arterial pressure (AP) and melatonin production in patients with essential hypertension (EH) stage II.
  
  
  METHODS
  Clinical, laboratory and device investigations covered 52 men with EH stage II (mean age 42 +/- 0.92 years) and 11 healthy men (mean age 23 +/- 1.46 years). Mean 24-hour, mean daytime, mean night systolic and diastolic pressures, 24-h index, time hypertensive index, standard deviation were registered. Melatonin was measured in the urine by radioimmunoassay. Geomagnetic situation was assessed by K-index (quiet--under 15, disturbed--15-25, magnetic storm--above 25).
  
  
  RESULTS
  In hypertensive patients AP grew with growth of geomagnetic activity. In normal subjects AP remained normal. The 24-h rhythm of AP variability in hypertensives was normal. Magnetic storm affected melatonin production in EH patients noticeably: night and daytime production of melatonin was low. In normal subjects night melatonin production was high.
  
  
  CONCLUSIONS
  AH stage II patients respond to magnetic storm with maladaptation, i.e. a rise in AP and low melatonin production.
authors.forename: S I
authors.initials: SI
authors.lastname: Rapoport
authors.forename: A M
authors.initials: AM
authors.lastname: Shatalova
authors.forename: V N
authors.initials: VN
authors.lastname: Oraevskiĭ
authors.forename: N K
authors.initials: NK
authors.lastname: Malinovskaia
authors.forename: L
authors.initials: L
authors.lastname: Vetterberg
mesh_terms: D000328:Adult; D001794:Blood Pressure / Q000528:radiation effects; D018534:Earth, Planet; D004574:Electromagnetic Fields; D006801:Humans; D006973:Hypertension / Q000378:metabolism* / Q000503:physiopathology; D008297:Male; D008550:Melatonin / Q000096:biosynthesis*
chemical_list: D008550:Melatonin