Hydrocortisone and vitamin D3 stimulation of 32Pi-phosphate accumulation by organ-cultured chick embryo duodenum.
Either vitamin D3 (or 1 alpha,25--(OH)2-D3) or hydrocortisone (HC) stimulated phosphate accumulation by organ-cultured embryonic chick duodenum. In combination, these two steroids stimulated phosphate uptake synergistically. Phosphate accumulation appeared to be independent of other vitamin D3-stimulated processes: CaBP concentration, cAMP concentration, or alkaline phosphatase activity. L-phenylalanine, a reported alkaline phosphatase inhibitor, when added to the culture medium progressively inhibited either D3- or HC-stimulated phosphate uptake subsequent to culture, but did not inhibit the synergistic action. Under these conditions L-phenylalanine had no consistent effect on alkaline phosphatase activity but unexpectedly, greatly inhibited vitamin D3-stimulated CaBP concentration, but only in the absence of HC. Some limited suggestion of an intestinal phosphoprotein sensitive to either vitamin D3 or HC was observed.
D000818:Animals; D002642:Chick Embryo; D002762:Cholecalciferol / Q000494:pharmacology*; D004100:Dihydroxycholecalciferols / Q000494:pharmacology; D004357:Drug Synergism; D004386:Duodenum / Q000187:drug effects; D006854:Hydrocortisone / Q000494:pharmacology*; D009924:Organ Culture Techniques; D010649:Phenylalanine / Q000494:pharmacology; D010710:Phosphates / Q000378:metabolism*; D064030:S100 Calcium Binding Protein G / Q000378:metabolism; D013997:Time Factors
D004100:Dihydroxycholecalciferols; D010710:Phosphates; D064030:S100 Calcium Binding Protein G; D002762:Cholecalciferol; D010649:Phenylalanine; D006854:Hydrocortisone