|
|
||||||||
AJP - Cell Physiology, Vol 263, Issue 3 C642-C652, Copyright © 1992 by American Physiological Society
ARTICLES |
A. M. Samarel, M. L. Spragia, V. Maloney, S. A. Kamal and G. L. Engelmann
Department of Medicine, Loyola University Stritch School of Medicine, Maywood, Illinois 60153.
Mechanical forces influence the growth and metabolism of a variety of cells, including cultured neonatal rat ventricular myocytes. To determine whether mechanical activity affected the synthesis and turnover of myosin heavy chain (MHC) in these striated muscle cells, MHC fractional degradative rates were measured in spontaneously beating cells and in arrested myocytes in which contractile activity was prevented by L-channel blockade (with verapamil, nifedipine, nisoldipine, and diltiazem) or K+ depolarization. MHC degradative rates were measured as the difference between rates of MHC synthesis and accumulation and in pulse-chase biosynthetic labeling experiments. Both methods indicated that contractile arrest markedly increased MHC degradation. Contractile arrest produced by L-channel blockade accelerated MHC degradation to a greater extent than K+ depolarization. The signal transduction pathway linking contractile activity to alterations in MHC degradation did not involve protein kinase C (PKC), because MHC degradation was unaffected by activating PKC in arrested cells or inhibiting PKC in spontaneously beating cells. Chloroquine and E-64 did not suppress the accelerated MHC degradation, suggesting that the rate-limiting step in MHC turnover occurred before degradative processing by cellular proteinases. Using a computer simulation, we hypothesize that the rate-limiting step in MHC turnover preceded (or was coincident with) MHC release from thick filaments. Thus mechanical forces may influence MHC half-life by regulating the rate of myosin disassembly.
This article has been cited by other articles:
![]() |
P. C. Geiger, J. P. Bailey, W.-Z. Zhan, C. B. Mantilla, and G. C. Sieck Denervation-induced changes in myosin heavy chain expression in the rat diaphragm muscle J Appl Physiol, August 1, 2003; 95(2): 611 - 619. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. B. Strait III, J. L. Martin, A. Bayer, R. Mestril, D. M. Eble, and A. M. Samarel Role of protein kinase C-{epsilon} in hypertrophy of cultured neonatal rat ventricular myocytes Am J Physiol Heart Circ Physiol, February 1, 2001; 280(2): H756 - H766. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. J. Yost, D. Simpson, K. Wrona, S. Ridley, H. J. Ploehn, T. K. Borg, and L. Terracio Design and construction of a uniaxial cell stretcher Am J Physiol Heart Circ Physiol, December 1, 2000; 279(6): H3124 - H3130. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. Kato, M. Sano, S. Miyoshi, T. Sato, D. Hakuno, H. Ishida, H. Kinoshita-Nakazawa, K. Fukuda, and S. Ogawa Calmodulin Kinases II and IV and Calcineurin Are Involved in Leukemia Inhibitory Factor-Induced Cardiac Hypertrophy in Rats Circ. Res., November 10, 2000; 87(10): 937 - 945. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. J. Sherman, F. J. Klocke, R. S. Decker, M. L. Decker, K. A. Kozlowski, K. R. Harris, S. Hedjbeli, Y. Yaroshenko, S. Nakamura, M. A. Parker, et al. Myofibrillar disruption in hypocontractile myocardium showing perfusion-contraction matches and mismatches Am J Physiol Heart Circ Physiol, April 1, 2000; 278(4): H1320 - H1334. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Miyata, W. Minobe, M. R. Bristow, and L. A. Leinwand Myosin Heavy Chain Isoform Expression in the Failing and Nonfailing Human Heart Circ. Res., March 3, 2000; 86(4): 386 - 390. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. Russell, D. Motlagh, and W. W. Ashley Form follows function: how muscle shape is regulated by work J Appl Physiol, March 1, 2000; 88(3): 1127 - 1132. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. H. Green, R. M. Glover, P. A. Krumm, T. R. Winters, and D. L. Atkins A soluble neuronal factor alters contractile function of ventricular myocytes without effect on troponin T isoform expression Cardiovasc Res, January 1, 1999; 41(1): 200 - 211. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. A. Makhlouf and P. J. McDermott Increased expression of eukaryotic initiation factor 4E during growth of neonatal rat cardiocytes in vitro Am J Physiol Heart Circ Physiol, June 1, 1998; 274(6): H2133 - H2142. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. M. Eble, M. Qi, S. Waldschmidt, P. A. Lucchesi, K. L. Byron, and A. M. Samarel Contractile activity is required for sarcomeric assembly in phenylephrine-induced cardiac myocyte hypertrophy Am J Physiol Cell Physiol, May 1, 1998; 274(5): C1226 - C1237. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. T. Ramirez, X.-L. Zhao, H. Schulman, and J. H. Brown The Nuclear delta B Isoform of Ca2+/Calmodulin-dependent Protein Kinase II Regulates Atrial Natriuretic Factor Gene Expression in Ventricular Myocytes J. Biol. Chem., December 5, 1997; 272(49): 31203 - 31208. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |