|
|
||||||||
Department of Physiology, University of Arizona, Tucson, Arizona 85724
In atherosclerosis and hypertension, vascular smooth muscle cells (SMCs) are stimulated to proliferate and exhibit enhanced gap junction protein expression. Our goal was to determine whether gap junction function differs in proliferating vs. growth-arrested SMCs. A7r5 cells (embryonic rat aortic SMCs) did not proliferate in media with reduced serum (~90% of cells in G0/G1 phase after 48-96 h in 1% fetal bovine serum). Dye coupling was less but electrical coupling was comparable in proliferating vs. growth-arrested A7r5 cells, suggesting differences in junctional permselectivity. In growth-arrested cells, junctional conductances measured with potassium glutamate, tetraethylammonium chloride, and KCl were well predicted by the conductivities of these solutions. In contrast, junctional conductances measured with potassium glutamate and tetraethylammonium chloride in proliferating cells were significantly greater than predicted by the conductivities of these solutions. These results suggest that junctions between growth-arrested cells are permeated equally well and simultaneously by anions and cations, whereas junctions between proliferating cells are poorly permeated by large molecules of either charge and equally well but not simultaneously by small anions and cations. The data indicate that A7r5 cells regulate chemical coupling independent of electrical coupling, a capacity that could facilitate growth control while protecting vasomotor responsiveness of vessels.
connexon; intercellular communication; permselectivity; cell cycle; growth control
This article has been cited by other articles:
![]() |
J. F. Ek-Vitorin and J. M. Burt Quantification of gap junction selectivity Am J Physiol Cell Physiol, December 1, 2005; 289(6): C1535 - C1546. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. T. Cottrell, R. Lin, B. J. Warn-Cramer, A. F. Lau, and J. M. Burt Mechanism of v-Src- and mitogen-activated protein kinase-induced reduction of gap junction communication Am J Physiol Cell Physiol, February 1, 2003; 284(2): C511 - C520. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. T. Cottrell, Y. Wu, and J. M. Burt Cx40 and Cx43 expression ratio influences heteromeric/ heterotypic gap junction channel properties Am J Physiol Cell Physiol, June 1, 2002; 282(6): C1469 - C1482. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. T. Cottrell and J. M. Burt Heterotypic gap junction channel formation between heteromeric and homomeric Cx40 and Cx43 connexons Am J Physiol Cell Physiol, November 1, 2001; 281(5): C1559 - C1567. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. M. Burt, A. M. Fletcher, T. D. Steele, Y. Wu, G. T. Cottrell, and D. T. Kurjiaka Alteration of Cx43:Cx40 expression ratio in A7r5 cells Am J Physiol Cell Physiol, March 1, 2001; 280(3): C500 - C508. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. Gu, J. F. Ek-Vitorin, S. M. Taffet, and M. Delmar Coexpression of Connexins 40 and 43 Enhances the pH Sensitivity of Gap Junctions : A Model for Synergistic Interactions Among Connexins Circ. Res., May 26, 2000; 86 (10): e98 - e103. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. O. Ruehlmann, C.-H. Lee, D. Poburko, and C. van Breemen Asynchronous Ca2+ Waves in Intact Venous Smooth Muscle Circ. Res., March 3, 2000; 86 (4): e72 - e79. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |