Stimulation of vitamin D-dependent Ca-ATPase and of intestinal caldium absorption by diphenylhydantoin.
The effects of diphenylhydantoin (DPH) and ouabain were studied in vitro on Mg-ATPase, Ca-ATPase and alkaline phosphatase (AlPase) in isolated brush borders from rat jejunum, and in vivo on intestinal calcium absorption. Vitamin D-deficient, -repleted and normal rats were used in this study. Repletion of deficient animals with vitamin D restored Ca-ATPase activity and AlPase activity partly. Ca-absorption was normalized by repletion with the vitamin. DPH greatly stimulated Ca-ATPase activity in vitro and Ca-absorption in vivo, but it inhibited AlPase activity. Mg-ATPase was not affected by vitamin D, nor by DPH. Ouabain had no consistent effect on any of the parameters studied. It was concluded that Ca-ATPase, and not AlPase, is involved in the transport of calcium through the jejunal microvillous membrane, and that DPH enhances Ca-absorption by activation of Ca-ATPase.
D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D066298:In Vitro Techniques; D007408:Intestinal Absorption / Q000187:drug effects*; D007413:Intestinal Mucosa / Q000201:enzymology / Q000648:ultrastructure; D007583:Jejunum / Q000648:ultrastructure; D008297:Male; D010672:Phenytoin / Q000494:pharmacology*; D051381:Rats; D013268:Stimulation, Chemical; D014807:Vitamin D / Q000494:pharmacology*; D014808:Vitamin D Deficiency / Q000378:metabolism / Q000473:pathology
D014807:Vitamin D; D010672:Phenytoin; D000469:Alkaline Phosphatase; D000251:Adenosine Triphosphatases; D002118:Calcium