title: Oxygen consumption and chloride secretion in rat distal colon isolated mucosa.
abstract: The aerobic metabolic cost of chloride secretion was studied in rat distal colon isolated mucosa under several conditions by simultaneous measurement of short-circuit current and oxygen consumption under conditions that preserve vectorial ion transport. A low-chloride solution and the presence of bumetanide plus diphenylamine-2-carboxylate reduced short-circuit current by 75% and oxygen consumption by 25%. Ouabain decreased short-circuit current by 93% and oxygen consumption by 32%. Serotonin increased both variables by 59% and 33%, respectively. Bumetanide and diphenylamine-2-carboxylate reduced but did not abolish the effect of serotonin on short-circuit current and oxygen consumption. Changes in short-circuit current and oxygen consumption were linearly correlated under all conditions tested. It is concluded that, in the unstimulated rat distal colon epithelium, chloride secretion accounts for about 75% of ouabain-sensitive short-circuit current and oxygen consumption. Stimulated chloride secretion may demand over 40% of total oxygen consumption.
authors.affiliation: Area Biofisica, Departmento de Morfofisiología, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, MZ 5500, Argentina.
authors.forename: Fernando D
authors.initials: FD
authors.lastname: Saraví
authors.forename: Teobaldo A
authors.initials: TA
authors.lastname: Saldeña
authors.forename: Cristian A
authors.initials: CA
authors.lastname: Carrera
authors.forename: Jorge E
authors.initials: JE
authors.lastname: Ibañez
authors.forename: Liliana M
authors.initials: LM
authors.lastname: Cincunegui
authors.forename: Graciela E
authors.initials: GE
authors.lastname: Carra
mesh_terms: D000818:Animals; D002712:Chlorides / Q000378:metabolism*; D003106:Colon / Q000378:metabolism*; D066298:In Vitro Techniques; D007413:Intestinal Mucosa / Q000378:metabolism*; D008297:Male; D010042:Ouabain / Q000494:pharmacology; D010101:Oxygen Consumption / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D012701:Serotonin / Q000494:pharmacology
chemical_list: D002712:Chlorides; D012701:Serotonin; D010042:Ouabain