title: Effect of hyperosmolarity on extracellular acidification associated with catecholamine secretion evoked by barium in perfused bovine adrenal medulla.
abstract: 1. The effects of the increase of osmotic strength on extracellular pH modifications produced during buffer-free, 5 mM Ba2+ stimulation was studied in decorticated perfused bovine adrenal glands. 2. A pronounced and reversible attenuation of the extracellular pH drop as well as of the release of catecholamines induced by Ba2+ was detected in glands exposed to a hyperosmotic (750 mOsm) perfusion fluid made up by the addition of NaCl. 3. Similar results were observed using sucrose as osmoticant instead of NaCl. 4. A progressive decline in both external acidification and secretory response to Ba2+ was found on gradually increasing the osmotic strength of the perfusion fluid. 5. These results provide additional evidence in favour of the existence of a close association between extracellular acidification and adrenomedullary secretion induced by buffer-free Ba2+.
authors.affiliation: Departamento de Fisiología, Facultad de Medicina, Universidad de Buenos Aires, Argentina.
authors.forename: P N
authors.initials: PN
authors.lastname: Viglione
authors.forename: C
authors.initials: C
authors.lastname: Gomez
authors.forename: J E
authors.initials: JE
authors.lastname: Pinto
mesh_terms: D000313:Adrenal Medulla / Q000187:drug effects* / Q000378:metabolism*; D000818:Animals; D001464:Barium / Q000494:pharmacology*; D002395:Catecholamines / Q000378:metabolism*; D002417:Cattle; D005069:Evaluation Studies as Topic; D005110:Extracellular Space / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D006982:Hypertonic Solutions; D066298:In Vitro Techniques; D009994:Osmolar Concentration; D010477:Perfusion; D012636:Secretory Rate / Q000187:drug effects
chemical_list: D002395:Catecholamines; D006982:Hypertonic Solutions; D001464:Barium