Abstract
In order to ascertain the role of calcium in maintaining the structure of the junctional complex between oxyntic cells, control gastric mucosae of the frog Rana pipiens were compared with those exposed to 1 to 4 mM ethylenediaminetetraacetic acid (EDTA). Changes in transmucosal potential difference and mucosal conductance were monitored. In one case a piece of EDTA-treated mucosa was washed and placed in a Ca++-containing solution. Material from all three categories was prepared for electron microscopy (glutaraldehyde and OsO4 fixation with Epon 812 embedding). Electron micrographs showed that after Ca++ depletion the intercellular electron-opaque material of the desmosome disappears and the walls of this component separate. Similar changes were observed in the zonula adhaerens. Consistent changes were difficult to detect in the zonula occludens although in some instances disorganization or separation within the tight junction was seen. These effects on the components of the junctional complex were reversible on readministration of Ca++. The results indicate that Ca++ is important in maintaining the integrity of the junctional complex. A model correlating the fine structural changes with physiological data is presented.
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- CURRAN P. F., GILL J. R., Jr The effect of calcium on sodium transport by frog skin. J Gen Physiol. 1962 Mar;45:625–641. doi: 10.1085/jgp.45.4.625. [DOI] [PMC free article] [PubMed] [Google Scholar]
- DORNFELD E. J., OWCZARZAK A. Surface responses in cultures fibroblasts elicited by ethylenediaminetetraacetic acid. J Biophys Biochem Cytol. 1958 May 25;4(3):243–250. doi: 10.1083/jcb.4.3.243. [DOI] [PMC free article] [PubMed] [Google Scholar]
- FARQUHAR M. G., PALADE G. E. Junctional complexes in various epithelia. J Cell Biol. 1963 May;17:375–412. doi: 10.1083/jcb.17.2.375. [DOI] [PMC free article] [PubMed] [Google Scholar]
- FORTE J. G., DAVIESRE Oxygen consumption and active transport of ions by isolated frog gastric mucosa. Am J Physiol. 1963 May;204:812–816. doi: 10.1152/ajplegacy.1963.204.5.812. [DOI] [PubMed] [Google Scholar]
- FORTE J. G., NAUSS A. H. EFFECTS OF CALCIUM REMOVAL ON BULLFROG GASTRIC MUCOSA. Am J Physiol. 1963 Oct;205:631–637. doi: 10.1152/ajplegacy.1963.205.4.631. [DOI] [PubMed] [Google Scholar]
- HAMA K. The fine structure of the desmosomes in frog mesothelium. J Biophys Biochem Cytol. 1960 Jun;7:575–578. doi: 10.1083/jcb.7.3.575. [DOI] [PMC free article] [PubMed] [Google Scholar]
- KARRER H. E. Cell interconnections in normal human cervical epithelium. J Biophys Biochem Cytol. 1960 Feb;7:181–184. doi: 10.1083/jcb.7.1.181. [DOI] [PMC free article] [PubMed] [Google Scholar]
- KAYE G. I., PAPPAS G. D., DONN A., MALLETT N. Studies on the cornea. II. The uptake and transport of colloidal particles by the living rabbit cornea in vitro. J Cell Biol. 1962 Mar;12:481–501. doi: 10.1083/jcb.12.3.481. [DOI] [PMC free article] [PubMed] [Google Scholar]
- LUFT J. H. Improvements in epoxy resin embedding methods. J Biophys Biochem Cytol. 1961 Feb;9:409–414. doi: 10.1083/jcb.9.2.409. [DOI] [PMC free article] [PubMed] [Google Scholar]
- MUIR A. R., PETERS A. Quintuple-layered membrane junctions at terminal bars between endothelial cells. J Cell Biol. 1962 Feb;12:443–448. doi: 10.1083/jcb.12.2.443. [DOI] [PMC free article] [PubMed] [Google Scholar]
- ODLAND G. F. The fine structure of the interrelationship of cells in the human epidermis. J Biophys Biochem Cytol. 1958 Sep 25;4(5):529–538. [PMC free article] [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]
- Ringer S., Sainsbury H. The Action of Potassium, Sodium and Calcium Salts on Tubifex Rivulorum. J Physiol. 1894 Mar 22;16(1-2):1–9. doi: 10.1113/jphysiol.1894.sp000490. [DOI] [PMC free article] [PubMed] [Google Scholar]
- SEDAR A. W. Electron microscopy of the oxyntic cell in the gastric glands of the bullfrog, Rana catesbiana. II. The acid-secreting gastric mucosa. J Biophys Biochem Cytol. 1961 May;10:47–57. doi: 10.1083/jcb.10.1.47. [DOI] [PMC free article] [PubMed] [Google Scholar]
- VIAL J. D., ORREGO H. Electron microscope observations on the fine structure of parietal cells. J Biophys Biochem Cytol. 1960 Apr;7:367–372. doi: 10.1083/jcb.7.2.367. [DOI] [PMC free article] [PubMed] [Google Scholar]
- WATSON M. L. The use of carbon films to support tissue sections for electron microscopy. J Biophys Biochem Cytol. 1955 Mar;1(2):183–184. doi: 10.1083/jcb.1.2.183. [DOI] [PMC free article] [PubMed] [Google Scholar]
- WHITTEMBURY G., SUGINO N., SOLOMON A. K. Effect of antidiuretic hormone and calcium on the equivalent pore radius of kidney slices from Necturus. Nature. 1960 Aug 20;187:699–701. doi: 10.1038/187699a0. [DOI] [PubMed] [Google Scholar]