title: Sodium deoxycholate inhibits chick duodenal calcium absorption through oxidative stress and apoptosis.
abstract: High concentrations of sodium deoxycholate (NaDOC) produce toxic effects. This study explores the effect of a single high concentration of NaDOC on the intestinal Ca(2+) absorption and the underlying mechanisms. Chicks were divided into two groups: 1) controls and 2) treated with different concentrations of NaDOC in the duodenal loop for variable times. Intestinal Ca(2+) absorption was measured as well as the gene and protein expressions of molecules involved in the Ca(2+) transcellular pathway. NaDOC inhibited the intestinal Ca(2+) absorption, which was concentration dependent. Ca(2+)-ATPase mRNA decreased by the bile salt and the same occurred with the protein expression of Ca(2+)-ATPase, calbindin D(28k) and Na(+)/Ca(2+) exchanger. NaDOC produced oxidative stress as judged by ROS generation, mitochondrial swelling and glutathione depletion. Furthermore, the antioxidant quercetin blocked the inhibitory effect of NaDOC on the intestinal Ca(2+) absorption. Apoptosis was also triggered by the bile salt, as indicated by the TUNEL staining and the cytochrome c release from the mitochondria. As a compensatory mechanism, enzyme activities of the antioxidant system were all increased. In conclusion, a single high concentration of NaDOC inhibits intestinal Ca(2+) absorption through downregulation of proteins involved in the transcellular pathway, as a consequence of oxidative stress and mitochondria mediated apoptosis.
authors.affiliation: Laboratorio Dr. Fernando Cañas, Cátedra de Bioquímica y Biología Molecular, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Pabellón Argentina, 2do. Piso, Ciudad Universitaria, 5000 Córdoba, Argentina.
authors.forename: María A
authors.initials: MA
authors.lastname: Rivoira
authors.forename: Ana M
authors.initials: AM
authors.lastname: Marchionatti
authors.forename: Viviana A
authors.initials: VA
authors.lastname: Centeno
authors.forename: Gabriela E
authors.initials: GE
authors.lastname: Díaz de Barboza
authors.forename: María E
authors.initials: ME
authors.lastname: Peralta López
authors.forename: Nori G
authors.initials: NG
authors.lastname: Tolosa de Talamoni
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism / Q000494:pharmacology; D017209:Apoptosis; D030161:Avian Proteins / Q000235:genetics / Q000378:metabolism; D064026:Calbindins; D002118:Calcium / Q000378:metabolism*; D002645:Chickens / Q000378:metabolism*; D045304:Cytochromes c / Q000378:metabolism; D003840:Deoxycholic Acid / Q000494:pharmacology / Q000502:physiology*; D004386:Duodenum / Q000378:metabolism*; D020895:Enterocytes / Q000378:metabolism; D015870:Gene Expression; D007408:Intestinal Absorption; D007413:Intestinal Mucosa / Q000166:cytology / Q000201:enzymology / Q000502:physiology; D008928:Mitochondria / Q000378:metabolism; D018384:Oxidative Stress; D053499:Plasma Membrane Calcium-Transporting ATPases / Q000235:genetics / Q000378:metabolism; D011794:Quercetin / Q000494:pharmacology; D017382:Reactive Oxygen Species / Q000378:metabolism; D064030:S100 Calcium Binding Protein G / Q000235:genetics / Q000378:metabolism; D019831:Sodium-Calcium Exchanger / Q000235:genetics / Q000378:metabolism
chemical_list: D000975:Antioxidants; D030161:Avian Proteins; D064026:Calbindins; D017382:Reactive Oxygen Species; D064030:S100 Calcium Binding Protein G; D019831:Sodium-Calcium Exchanger; C110374:sodium-calcium exchanger 1; D003840:Deoxycholic Acid; D045304:Cytochromes c; D011794:Quercetin; D053499:Plasma Membrane Calcium-Transporting ATPases; D002118:Calcium