title: Dietary magnesium deficiency decreases plasma melatonin in rats.
abstract: It has been postulated that Mg depletion is associated with decreased melatonin. Exogenous magnesium (Mg) has been found to increase the activity of serotonin N-acetyltransferase, an enzyme in the pathway for melatonin synthesis; but no data have been found on the effect of Mg deficiency on plasma melatonin. This pilot study examined the effect of a dietary Mg deficiency on plasma melatonin in male, Sprague-Dawley rats. Weanling rats were placed on a Mg-deficient (150 ppm) or a Mg-adequate (1000 ppm) diets for four weeks, after which they were sacrificed 4, 5 or 7 hours into the dark cycle. Plasma was assayed for melatonin concentrations. A significant decrease (p = 0.0101) occurred in mean (+/- SEM) plasma melatonin levels of the Mg-deficient animals (50 +/- 6.4 pg/mL) when compared to the Mg-adequate animals (75 +/- 6.6 pg/mL). There was no obvious phase shift in the melatonin profile of the Mg-deficient animals when compared to the Mg-adequate animals.
authors.affiliation: Department of Nutrition, Dietetics and Food Science, Brigham Young University, Provo, UT 84602, USA.
authors.forename: A J
authors.initials: AJ
authors.lastname: Billyard
authors.forename: D L
authors.initials: DL
authors.lastname: Eggett
authors.forename: K B
authors.initials: KB
authors.lastname: Franz
mesh_terms: D000818:Animals; D003624:Darkness; D004032:Diet; D008275:Magnesium Deficiency / Q000097:blood*; D008297:Male; D008550:Melatonin / Q000097:blood*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D008550:Melatonin