Publication Date

1-1-1996

Document Type

Dissertation/Thesis

First Advisor

Gasser, Kenneth W.

Degree Name

B.S. (Bachelor of Science)

Legacy Department

Department of Biological Sciences

Abstract

Pancreatic secretory granules contain electrolyte transport pathways for Cl⁻ and K⁺ that may contribute to exocyto- tic membrane fusion or net fluid secretion following membrane fusion. Recently the granule K⁺ transport pathway was shown to exhibit characteristics of the ATP-sensitive K⁺ channels which include inhibition by ATP. K⁺ transport by the zymogen granule membrane was measured indirectly following K+ dependent osmotic swelling and ionophore-induced lysis of the granule while incubated in KC1 and sucrose solutions, pH 7.0, at 37°C. This lysis rate was K⁺ dependent and ATP inhibited. The results also show that this granule K⁺ transport pathway can be activated by cAMP- dependent protein kinase phosphorylation. ATP reduced the K⁺ dependent rate in a dose dependent manner. Subsequent incubation of apical plasma membranes with 15 units/ml of the catalytic subunit of protein kinase A restored K⁺ transport in fusion experiments. Although protein kinase C induced K⁺ transport was not elevated over control levels, the results of protein kinase A stimulated K⁺ transport support the assertion of ATP-sensitive K⁺ transport by secretory granules. This suggests a mechanism for the regulation of secretory granules consistent with the known signaling mechanisms controlling stimulus-secretion coupling in pancreatic acinar cells.

Comments

Includes bibliographical references.

Extent

29 unnumbered pages

Language

eng

Publisher

Northern Illinois University

Rights Statement

In Copyright

Rights Statement 2

NIU theses are protected by copyright. They may be viewed from Huskie Commons for any purpose, but reproduction or distribution in any format is prohibited without the written permission of the authors.

Media Type

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