Permeability changes induced by electric impulses in vesicular membranes
Tóm tắt
Electric impulses were found to cause transient permeability changes in the membranes of vesicles storing biogenic amines. Release of catecholamines induced by electric fields (of the order of 20 kV/cm and decaying exponentially with a decay time of about 150 μsec) was studied, using the chromaffin granules of bovine adrenomedullary cells as a vesicular model system. Far-UV-absorption spectroscopy was applied to determine the amount of catecholamines released from suspended vesicles. A polarization mechanism is suggested for the induction of short-lived permeability changes caused by electric fields. Such transient changes in permeability may possibly represent a part of the sequence of events leading to stimulated neurohumoral secretion.
Tài liệu tham khảo
Banks, P. 1966. An interaction between chromaffin granules and calcium ions.Biochem. J. 101:18C.
Bloom, F. E., Iversen, L. L., Schmitt, F. O. 1970. Macromolecules in synaptic function.Neurosci. Res. Prog. Bull. 8:325.
Duysens, L. N. M. 1956. The flattening of the absorption spectrum of suspensions, as compared to that of solutions.Biochim. Biophys. Acta 19:1.
Eigen, M., De Maeyer, L. 1963. Relaxation methods.In: Technique of Organic Chemistry. S. L. Friess, E. S. Lewis, and A. Weissberger, editors. Vol. 8, Pt. 2, p. 895. Interscience Publishers, Inc., New York.
Euler, U. S. von. 1970. Adrenergic neurotransmitter functions.Science 173:202.
Helle, K. B., Flatmark, T., Serck-Hanssen, G., Lönning, S. 1971. An improved method for the large-scale isolation of chromaffin granules from bovine adrenal medulla.Biochim. Biophys. Acta 226:1.
Hillarp, N. A. 1958. The release of catecholamines from the amine containing granules of the adrenal medulla.Acta Physiol. Scand. 43:292.
Kornberg, R. D., McConnell, H. M. 1971. Lateral diffusion of phospholipids in a vesicle membrane.Proc. Nat. Acad. Sci. 68:2564.
Lowry, O. H., Rosenbrough, N. J., Farr, A. L., Randall, R. J. 1951. Protein measurement with the Folin phenol reagent.J. Biol. Chem. 193:265.
Neumann, E., Katchalsky, A. 1972. Long-lived conformation changes induced by electric impulses in biopolymers.Proc. Nat. Acad. Sci. 69:993.
Schwarz, G. 1962. A theory of the low-frequency dielectric dispersion of colloidal particles in electrolyte solution.J. Phys. Chem. 66:2636.
Smith, A. D. 1968. Biochemistry of adrenal chromaffin granules.In: The Interaction of Drugs and Subcellular Components in Animal Cells. P. N. Campbell, editor. p. 239. J. & A. Churchill, Ltd., London.
Stein, W. D. 1967. The Movements of Molecules across Cell Membranes. p. 36. Academic Press Inc., New York.
Trifaró, J. M., Dworkind, J. 1970. A new and simple method for isolation of adrenal chromaffin granules by means of an isotonic density gradient.Analyt. Biochem. 34:403.
Wiersema, P. H., Loeb, A. L., Overbeek, J. T. G. 1966. Calculation of the electrophoretic mobility of a spherical colloid particle.J. Colloid Interface Sci. 22:78.