Effect of 1 alpha-hydroxycholecalciferol administration on Mg metabolism in sheep.
The effect of 1 alpha-hydroxycholecalciferol (1 alpha-OH-D3) administration on Mg metabolism in sheep was studied. Three wethers were intramuscularly injected with 0.2 microgram/kg body weight of 1 alpha-OH-D3 for 3 days. Plasma Mg concentration was decreased and plasma Ca concentration was increased by 1 alpha-OH-D3 administration. However, the duration of hypomagnesemia was shorter than that of the increment in the plasma Ca concentration. The administration of 1 alpha-OH-D3 increased apparent Ca absorption and urinary Ca excretion. However, apparent absorption and urinary excretion of Mg was not changed by 1 alpha-OH-D3 administration. The amount of glomerular filtrated Mg was reduced concomitantly with the reduction of plasma Mg concentration and glomerular filtration rate when 1 alpha-OH-D3 was injected. The tubular reabsorption of Mg tended to be suppressed and the ratio of reabsorbed to filtrated Mg was significantly lowered by 1 alpha-OH-D3 administration. These results suggested that the stimulation of urinary Mg excretion might not be one of the major factors inducing hypomagnesemia although 1 alpha-OH-D3 suppressed reabsorption of Mg in the renal tubule.
Matsui
T
T
Faculty of Agriculture, Shimane University, Matsue, Japan.
Harumoto
T
T
Yano
H
H
Kawashima
R
R
D000042:Absorption; D000818:Animals; D002118:Calcium / Q000097:blood / Q000652:urine; D005260:Female; D005919:Glomerular Filtration Rate / Q000187:drug effects; D006887:Hydroxycholecalciferols / Q000494:pharmacology*; D007684:Kidney Tubules / Q000187:drug effects / Q000378:metabolism; D007700:Kinetics; D008274:Magnesium / Q000097:blood / Q000378:metabolism* / Q000652:urine; D012756:Sheep / Q000097:blood*
D006887:Hydroxycholecalciferols; D008274:Magnesium; D002118:Calcium; C008088:alfacalcidol