Bile salt deficiency and the absorption of vitamin D metabolites. In vivo study in the rat.
We studied the effect of the absence of bile salts on the absorption of vitamin D metabolites in vivo, in the biliary duct-ligated rat. The mesenteric, lymphatic absorption of the metabolites studied (vitamin D3, 25-hydroxyvitamin D3, and 1,25-dihydroxyvitamin D3) was almost completely abolished in the experimental animals. These results differed significantly (P less than 0.001) from those of the control rats. The 1,25-dihydroxyvitamin D3 absorption into the portal vein system was unaffected by the lack of biliary salts. The absorption of 25-hydroxyvitamin D3 was decreased and that of vitamin D3 was negligible, under the same experimental conditions. These data show that the more polar vitamin D metabolites, like 1,25-dihydroxyvitamin D3 and to some extent 25-hydroxyvitamin D3, are absorbed directly into the portal blood without the involvement of bile salts and micelle formation. Thus, the use of polar vitamin D metabolites should be considered in correcting hypovitaminosis D and osteomalacia in cases of chronic biliary salt depletion.
Maislos
M
M
Department of Medicine C, Toor Institute, Soroka Medical Center, Beer Sheva, Israel.
Shany
S
S
D000818:Animals; D001647:Bile Acids and Salts / Q000502:physiology*; D002112:Calcifediol / Q000378:metabolism*; D002117:Calcitriol / Q000378:metabolism*; D002762:Cholecalciferol / Q000378:metabolism*; D003135:Common Bile Duct / Q000601:surgery; D007408:Intestinal Absorption; D008026:Ligation; D008297:Male; D008823:Micelles; D011168:Portal System / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains
D001647:Bile Acids and Salts; D008823:Micelles; D002762:Cholecalciferol; D002117:Calcitriol; D002112:Calcifediol