Abstract
1. The voltage transient developed across rabbit foetal gastric mucosa in response to rectangular current pulses was measured under in vitro conditions. The short-circuit current was also measured.
2. The voltage transients were used to calculate equivalent circuit parameters. The mucosa could be represented as two large capacitances in series, each shunted by a high conductance.
3. Electron microscopy was carried out on some preparations after the electrical measurements had been made. An extensive smooth membrane tubular system was observed on the apical sides of the cells, with openings into the gastric lumen.
4. Anoxia resulted in a reversible reduction in value of the large capacitance and short-circuit current: the relative changes in these two quantities were very closely linked. Electron microscopy showed a large and reversible decline in the extent of the apical tubular system during anoxia.
5. It was concluded that the apical tubular system plays an important role in ion transport in this preparation. Considerations of the magnitude of the capacitances and of membrane area suggest that the smaller capacitor represents the plasma membrane. The dieletric constant of the smooth membrane of the tubular system is an order of magnitude lower than that of the plasma membrane.
Full text
PDF














Images in this article
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Brown A. C., Kastella K. G. The AC impedance of frog skin and its relation to active transport. Biophys J. 1965 Jul;5(4):591–606. doi: 10.1016/S0006-3495(65)86736-4. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Farquhar M. G., Palade G. E. Adenosine triphosphatase localization in amphibian epidermis. J Cell Biol. 1966 Aug;30(2):359–379. doi: 10.1083/jcb.30.2.359. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Forte T., Forte J. G. A freeze-fracture study of bullfrog gastric oxyntic cells. J Ultrastruct Res. 1971 Nov;37(3):322–334. doi: 10.1016/s0022-5320(71)80127-2. [DOI] [PubMed] [Google Scholar]
- Kendal A Wright G. H. Active transport of ions by the gastric mucosa of the rabbit foetus. J Physiol. 1967 Jun;190(3):531–540. doi: 10.1113/jphysiol.1967.sp008226. [DOI] [PMC free article] [PubMed] [Google Scholar]
- LILLIBRIDGE C. B. THE FINE STRUCTURE OF NORMAL HUMAN GASTRIC MUCOSA. Gastroenterology. 1964 Sep;47:269–290. [PubMed] [Google Scholar]
- Noyes D. H., Rehm W. S. Voltage response of frog gastric mucosa to direct current. Am J Physiol. 1970 Jul;219(1):184–192. doi: 10.1152/ajplegacy.1970.219.1.184. [DOI] [PubMed] [Google Scholar]
- PEACHEY L. D., RASMUSSEN H. Structure of the toad's urinary bladder as related to its physiology. J Biophys Biochem Cytol. 1961 Aug;10:529–553. doi: 10.1083/jcb.10.4.529. [DOI] [PMC free article] [PubMed] [Google Scholar]
- REHM W. S. The gastric potential and its role in the secretion of acid. Am J Dig Dis. 1959 Mar;4(3):194–207. doi: 10.1007/BF02231223. [DOI] [PubMed] [Google Scholar]
- ROHRER G. V., SCOTT J. R., JOEL W., WOLF S. THE FINE STRUCTURE OF HUMAN GASTRIC PARIETAL CELLS. Am J Dig Dis. 1965 Jan;10:13–21. doi: 10.1007/BF02235070. [DOI] [PubMed] [Google Scholar]
- Sedar A. W. Fine structure of the stimulated oxyntic cell. Fed Proc. 1965 Nov-Dec;24(6):1360–1367. [PubMed] [Google Scholar]
- Smith P. G. The low-frequency electrical impedance of the isolated frog skin. Acta Physiol Scand. 1971 Mar;81(3):355–366. doi: 10.1111/j.1748-1716.1971.tb04910.x. [DOI] [PubMed] [Google Scholar]
- USSING H. H., ZERAHN K. Active transport of sodium as the source of electric current in the short-circuited isolated frog skin. Acta Physiol Scand. 1951 Aug 25;23(2-3):110–127. doi: 10.1111/j.1748-1716.1951.tb00800.x. [DOI] [PubMed] [Google Scholar]
- WRIGHT G. H. Net transfers of water, sodium, chloride and hydrogen ions across the gastric mucosa of the rabbit foetus. J Physiol. 1962 Sep;163:281–293. doi: 10.1113/jphysiol.1962.sp006974. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wright G. H. Oxygen uptake and active transport of sodium by the foetal gastric mucosa. J Physiol. 1971 Jan;212(2):40P–41P. [PubMed] [Google Scholar]