The role of the liver in the metabolism of vitamin D.
The metabolism of vitamin D(3) has been studied after intravenous injection of 10 IU of [1,2-(3)H]-vitamin D(3) to vitamin D-deficient rats. The disappearance of the radioactivity from the plasma follows a very peculiar pattern characterized by an early rapid disappearance followed by a rebound of radioactivity before assuming still a third rather slow disappearance rate. The "rebound" phenomenon is concomitant with a rapid release of the radioactivity from the liver and is accounted for by the appearance of 25-hydroxycholecalciferol and other metabolites in the blood. It is postulated that the liver is the major site of transformation of vitamin D(3) into 25-hydroxycholecalciferol.
D000818:Animals; D001711:Biotransformation; D002762:Cholecalciferol / Q000097:blood / Q000378:metabolism*; D002845:Chromatography; D007275:Injections, Intravenous; D008099:Liver / Q000378:metabolism*; D008297:Male; D051381:Rats; D014316:Tritium; D014808:Vitamin D Deficiency / Q000378:metabolism
D014316:Tritium; D002762:Cholecalciferol