|
|
||||||||
Departments of 1 Physiology and Biophysics and 2 Anatomy and Cell Biology, University of Calgary Health Sciences Centre, Calgary, Alberta, Canada T2N 4N1
A
sustained K+ current (Iss) is
attenuated in ventricular cells from streptozotocin (STZ)-induced
diabetic rats. The in vitro addition of insulin to isolated cells
augments Iss in a process that is blocked by
disrupting either actin microfilaments (with cytochalasin D) or
microtubules (with colchicine). When these agents are added at
progressively later times, the effect of insulin becomes evident in a
time-dependent manner. Iss is also augmented by
insulin in control cells in a cytoskeleton-dependent manner. However,
in contrast to diabetic cells, cytoskeleton-dependent augmentation of
Iss by insulin occurs at a considerably faster rate in control cells. Immunofluorescent labeling shows a reduced density of
-tubulin in diabetic cells, particularly in perinuclear regions. In vitro insulin replacement or in vivo insulin injections given to STZ-treated rats enhances
-tubulin density. These results suggest an impairment of cytoskeleton function and structure under insulin-deficient conditions, which may have implications for cardiac function.
cardiac potassium channels; microtubules; actin microfilaments
This article has been cited by other articles:
![]() |
Y. Zhang, J. S. Helm, A. Senatore, J. D. Spafford, L. K. Kaczmarek, and E. A. Jonas PKC-Induced Intracellular Trafficking of CaV2 Precedes Its Rapid Recruitment to the Plasma Membrane J. Neurosci., March 5, 2008; 28(10): 2601 - 2612. [Abstract] [Full Text] [PDF] |
||||
![]() |
N. Yaras, M. Ugur, S. Ozdemir, H. Gurdal, N. Purali, A. Lacampagne, G. Vassort, and B. Turan Effects of Diabetes on Ryanodine Receptor Ca Release Channel (RyR2) and Ca2+ Homeostasis in Rat Heart Diabetes, November 1, 2005; 54(11): 3082 - 3088. [Abstract] [Full Text] [PDF] |
||||
![]() |
Z. Wang, J. R. Eldstrom, J. Jantzi, E. D. Moore, and D. Fedida Increased focal Kv4.2 channel expression at the plasma membrane is the result of actin depolymerization Am J Physiol Heart Circ Physiol, February 1, 2004; 286(2): H749 - H759. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. F del Valle, E. C Lascano, and J. A Negroni Ischemic preconditioning protection against stunning in conscious diabetic sheep: role of glucose, insulin, sarcolemmal and mitochondrial KATP channels Cardiovasc Res, August 15, 2002; 55(3): 642 - 659. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Calaghan, E. White, and J.-Y. Le Guennec A Unifying Mechanism for the Role of Microtubules in the Regulation of [Ca2+]i and Contraction in the Cardiac Myocyte Circ. Res., September 14, 2001; 89 (6): e31 - e31. [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |