Ionic relationships of the bioelectrogenic mechanism in isolated rat stomach

• Published in: Biochimica et biophysica acta Vol. 94; no. 1; pp. 280 - 292
• Main Authors: Cummins, J.T., Vaughan, B.E.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 25.01.1965
• Subjects: Anions; Arsenicals; Chloromercuribenzoates; Choline; Cyanides; Dinitrophenols; Edetic Acid; Fluorides; Gastric Mucosa; Hypoxia; Iodoacetates; Ions; Malonates; Old Medline; Ouabain; Pharmacology; Radiometry; Rats; Sodium; Sodium Isotopes; Stomach; RADIOMETRY; SODIUM; CHOLINE; IODOACETATES; EXPERIMENTAL LAB STUDY; RATS; SODIUM ISOTOPES; EDTA; GASTRIC MUCOSA; MALONATES; FLUORIDES; OUABAIN; ANOXIA; PHARMACOLOGY; CHLOROMERCURIBENZOATES; DINITROPHENOLS; ARSENICALS; CYANIDES
• ISSN: 0926-6585; 0006-3002
• DOI: 10.1016/0926-6585(65)90032-4

The potential as measured in vitro across rat stomach has been examined by substitution, inhibition and flux studies. The effect of choline substitution for Na + on the potential was shown to be immediate, and to act on the mucosal influx, changing it from 1.8 to 0.4 μequiv of Na + per min. Anoxic condition most dramatically increased the mucosal outflux. The transmembrane potential was found to be linearly dependent on mucosal Na + concentration to 55 mM, where the system apparently became saturated. Replacement of Cl − by SO 4 2− raised the potential. A K + requirement could be demonstrated by the elimination of Cl −, and a Ca 2+ deficiency was noted only in the presence of high concentrations of EDTA. 2,4-Dinitrophenol was shown to be the most effective of a series of metabolic inhibitors. Gastric mucosa was shown to possess an ATPase, stimulated by Na + and K + and inhibited by ouabain. All these results point to the conclusion that the potential difference across isolated rat stomach is generated by a Na + transport mechanism, as characterized by others in different tissues.