Compartmental analysis of magnesium kinetics in Mg-sufficient and Mg-deficient rats.
In this study, we determined magnesium kinetic values in normal rats using stable-isotope techniques. Additionally, we calculated the mass of the exchangeable pools of Mg in Mg-deficient rats to determine whether it can be used as a marker of Mg status. Rats were fed either a control diet (1,000 mg Mg/kg) or a Mg-deficient diet (60 mg Mg/kg). After 2 weeks on the experimental diets, each rat received an intravenous injection of 26Mg. The plasma Mg disappearance curve over the next 7 days was used to measure the mass and fractional transport rate of 3 rapidly exchanging Mg metabolic pools. In control rats, the mass of pool 1 (1.37 mg) was half that of pool 2 (2.46 mg), and pool 3 (47.7 mg) accounted for greater than 90% of exchangeable Mg. In Mg-deficient rats, we observed a significant decrease in the size of the 3 exchangeable pools of Mg (0.36, 0.72, and 20.2 mg, respectively) relative to the control rats. Furthermore, the fractional transport rate of Mg from pool 1 to pool 3 in Mg-deficient rats was 3 times the rate in the control rats, and the rate of irreversible loss from pool 1 was lower in Mg-deficient rats. In summary, this study allows us to establish Mg kinetic data in Mg-sufficient and Mg-deficient rats. The present experiment supports the conclusion that the isotopic test identifies animals with severe Mg deficiency.
Feillet-Coudray
C
C
Centre de Recherche en Nutrition Humaine d'Auvergne, Unité Maladies Métaboliques et Micronutriments, Institut National de la Recherche Agronomique, Saint Genès Champanelle, France.
Coudray
C
C
Gueux
E
E
Ducros
V
V
Mazur
A
A
Abrams
S
S
Rayssiguier
Y
Y
D000818:Animals; D007700:Kinetics; D008274:Magnesium / Q000378:metabolism*; D008275:Magnesium Deficiency / Q000378:metabolism*; D008297:Male; D008954:Models, Biological; D051381:Rats; D017208:Rats, Wistar
D008274:Magnesium