title: Intestinal Na(+)/Ca(2+) exchanger protein and gene expression are regulated by 1,25(OH)(2)D(3) in vitamin D-deficient chicks.
abstract: The role of 1,25(OH)(2)D(3) on the intestinal NCX activity was studied in vitamin D-deficient chicks (-D) as well as the hormone effect on NCX1 protein and gene expression and the potential molecular mechanisms underlying the responses. Normal, -D and -D chicks treated with cholecalciferol or 1,25(OH)(2)D(3) were employed. In some experiments, -D chicks were injected with cycloheximide or with cycloheximide and 1,25(OH)(2)D(3) simultaneously. NCX activity was decreased by -D diet, returning to normal values after 50 IU daily of cholecalciferol/10 days or a dose of 1μg calcitriol/kg of b.w. for 15 h. Cycloheximide blocked NCX activity enhancement produced by 1,25(OH)(2)D(3). NCX1 protein and gene expression were diminished by -D diet and enhanced by 1,25(OH)(2)D(3). Vitamin D receptor expression was decreased by -D diet, effect that disappeared after 1,25(OH)(2)D(3) treatment. Rapid effects of 1,25(OH)(2)D(3) on intestinal NCX activity were also demonstrated. The abolition of the rapid effects through addition of Rp-cAMPS and staurosporine suggests that non genomic effects of 1,25(OH)(2)D(3) on NCX activity are mediated by activation of PKA and PKC pathways. In conclusion, 1,25(OH)(2)D(3) enhances the intestinal NCX activity in -D chicks through genomic and non genomic mechanisms.
authors: Laboratorio Dr. Fernando Cañas, Bioquímica y Biología Molecular, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Córdoba, Argentina.
authors: Viviana
authors: V
authors: Centeno
authors: Gabriela
authors: G
authors: Picotto
authors: Adriana
authors: A
authors: Pérez
authors: Arturo
authors: A
authors: Alisio
authors: Nori
authors: N
authors: Tolosa de Talamoni
mesh_terms: D000818:Animals; D002117:Calcitriol / Q000494:pharmacology* / Q000627:therapeutic use; D002120:Calcium Channel Agonists / Q000494:pharmacology* / Q000627:therapeutic use; D002645:Chickens; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects*; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000187:drug effects; D011493:Protein Kinase C / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D019831:Sodium-Calcium Exchanger / Q000378:metabolism*; D014807:Vitamin D / Q000378:metabolism; D014808:Vitamin D Deficiency / Q000188:drug therapy / Q000378:metabolism*; D014815:Vitamins / Q000494:pharmacology* / Q000627:therapeutic use
chemical_list: D002120:Calcium Channel Agonists; D019831:Sodium-Calcium Exchanger; D014815:Vitamins; D014807:Vitamin D; D017868:Cyclic AMP-Dependent Protein Kinases; D011493:Protein Kinase C; D002117:Calcitriol