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Title: Melatonin secretion and puberty in female lambs exposed to environmental electric and magnetic fields

This study determined whether chronic exposure of female lambs to the electric and magnetic fields (EMF) of a high voltage transmission line can alter pineal secretion of melatonin and the normal occurrence of puberty. Twenty female Suffolk lambs were assigned randomly in equal numbers to a control and a treatment group. Treatment from 2 to 10 mo of age consisted of continuous exposure within the electrical environment of a 500-kV transmission line (mean electric field 6 kV/m, mean magnetic field 40 mG). Treated lambs were penned directly beneath the transmission line; control lambs were maintained in a pen of similar construction 229 m from the line where EMF were at ambient levels (mean electric field < 10 V/m, mean magnetic field < 0.3 mG). Melatonin was analyzed by RIA in serum of blood samples collected at 0.5-3-h intervals over eight 48-h periods. To assess attainment of puberty, serum concentrations of progesterone were determined by RIA from blood samples collected twice weekly beginning at 19 wk of age. Concentrations of circulating melatonin in control and treated lambs were low during daylight hours and increased during nighttime hours. The characteristic pattern of melatonin secretion during nighttime (amplitude, phase, and duration) did notmore » differ between control and treatment groups. Age at puberty and number of subsequent estrous cycles also did not differ between groups. These data suggest that chronic exposure of developing female sheep to 60-Hz environmental EMF does not affect the mechanisms underlying the generation of the circadian pattern of melatonin secretion or the mechanisms involved in the onset of reproductive activity.« less
Authors:
; ; ; ; ; ; ; ;  [1]
  1. (Oregon State Univ., Corvallis (United States))
Publication Date:
OSTI Identifier:
5505956
Resource Type:
Journal Article
Resource Relation:
Journal Name: Biology of Reproduction; (United States); Journal Volume: 49:4
Country of Publication:
United States
Language:
English
Subject:
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.; ELECTROMAGNETIC FIELDS; BIOLOGICAL EFFECTS; FEMALES; ESTROUS CYCLE; MELATONIN; SECRETION; SHEEP; BLOOD CHEMISTRY; CHRONIC EXPOSURE; DAILY VARIATIONS; ENVIRONMENTAL EXPOSURE; LIFE CYCLE; PINEAL GLAND; PROGESTERONE; AMINES; ANIMALS; AROMATICS; AZAARENES; AZOLES; BIOCHEMISTRY; BODY; CHEMISTRY; DOMESTIC ANIMALS; GLANDS; HETEROCYCLIC COMPOUNDS; HORMONES; INDOLES; KETONES; MAMMALS; ORGANIC COMPOUNDS; ORGANIC NITROGEN COMPOUNDS; ORGANS; PREGNANES; PYRROLES; RUMINANTS; STEROID HORMONES; STEROIDS; TRYPTAMINES; VARIATIONS; VERTEBRATES 560400* -- Other Environmental Pollutant Effects