Summary
Particle microeleetrophoresis has been used to measure the surface charge of secretory granules isolated from the exocrine and endocrine pancreas of guineapigs. Zymogen granules were found to have a surface charge density of 2378 esu.cm−2 and islet granules 4177 esu.cm−2. Calcium ions decreased the surface charge density of both types of granule; binding of calcium at the zymogen granule surface was found to fit a Langmuir adsorption isotherm. The results are discussed with respect to the role of calcium in exocytosis.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
Dean, P.M.: Ultrastructural morphometry of the pancreaticβ-cell. Diabetologia9, 115–119 (1973)
Dean, P.M., Matthews, E.K.: Glucose-induced electrical activity in pancreatic islet cells. J. Physiol.210, 255–264 (1970)
Dean, P.M., Matthews, E.K.: Calcium-ion binding to the chromaffin granule surface. Biochem. J. (In Press)
Heard, D.H., Seaman, G.V.F.: The influence of pH and ionic strength on the electrokinetic stability of the human erythrocyte membrane. J. gen. Physiol.43, 635–654 (1960)
Howell, S.L., Fink, C.J., Lacy, P.E.: Isolation and properties of secretory granules from rat islets of Langerhans. 1. Isolation of a secretory granule fraction. J. Cell. Biol.41, 154–161 (1969)
Jamieson, J.D., Palade, G.E.: Intracellular transport of secretory proteins in the pancreatic exocrine cell. J. Cell. Biol.34, 577–596 (1967)
Lacy, P.E., Kostianovsky, M.: Method for the isolation of intact islets of Langerhans from the rat pancreas. Diabetes16, 35–39 (1967)
Matthews, E.K.: Calcium and hormone released. In: Calcium and Cell Function, ed. Cuthbert, A.W. p. 163. London: Macmillan 1970
Matthews, E.K.: Electrical activity in islet cells and insulin secretion. Acta Diabet. Lat.7, 83–89 (1970)
Matthews, E.K., Dean, P.M., Sakamoto, Y.: The bioelectrical activity of the islet cell membrane. In: Handbook of Experimental Pharmacology. Vol. 32/2. Insulin 2. (Ed Hasselblatt, A. & Von Bruckhausen.) Berlin, Heidelberg, New York: Springer-Verlag (In Press)
Matthews, E.K., Evans, R.J., Dean, P.M.: The ionogenic nature of the secretory granule surface. Electrokinetic properties of isolated chromaffin granules. Biochem. J.130, 825–832 (1972)
Seaman, G.V.F., Vassar, P.S., Kendall, M.J.: Calcium-ion binding to blood cell surfaces. Experientia25, 1259–1260 (1969)
Stern, O., Zur Theorie der Elektrolytischen Doppelschicht. Z. Elektrochem.30, 508–516 (1924)
Author information
Authors and Affiliations
Additional information
Beit Memorial Research Fellow.
Rights and permissions
About this article
Cite this article
Dean, P.M. Surface electrostatic-charge measurements on islet and zymogen granules: Effect of calcium ions. Diabetologia 10, 427–430 (1974). https://doi.org/10.1007/BF01221633
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF01221633