| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
1 Department of Physiology and Biophysics, Wright State University School of Medicine, Dayton, Ohio 45435; 2 School of Pharmacy, Kuwait University; and 3 Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta, Georgia 30912-2300
H2O2 is a reactive oxygen species that contracts or relaxes vascular smooth muscle, but the molecular basis of these effects remains obscure. We previously demonstrated that H2O2 opens the large-conductance, calcium- and voltage-activated (BKCa) potassium channel of coronary myocytes (2) and now report physiological and biochemical evidence that the effect of H2O2 on coronary smooth muscle involves the phospholipase A2 (PLA2)/arachidonic acid (AA) signaling cascades. H2O2 stimulation of BKCa channel activity was inhibited by arachidonyl trifluoromethyl ketone, an inhibitor of cytosolic PLA2. Furthermore, H2O2 stimulated release of [3H]AA from coronary myocytes, and exogenous AA mimicked the effect of H2O2 on BKCa channels. Inhibitors of protein kinase C activity attenuated the effect of H2O2 on BKCa channels, [3H]AA release, or intact coronary arteries. In addition, the effect of H2O2 or AA on BKCa channels was inhibited by blockers of lipoxygenase metabolism. In contrast, inhibitors of cyclooxygenase or cytochrome P-450 had no effect. We propose that H2O2 relaxes coronary arteries by stimulating BKCa channels via the PLA2/AA signaling cascade and that lipoxygenase metabolites mediate this response.
hydrogen peroxide; calcium- and voltage-activated channels; phospholipase A2
This article has been cited by other articles:
|
|
 |
|
  D.-L. Dong, Y. Zhang, D.-H. Lin, J. Chen, S. Patschan, M. S. Goligorsky, A. Nasjletti, B.-F. Yang, and W.-H. Wang Carbon Monoxide Stimulates the Ca2+ Activated Big Conductance K Channels in Cultured Human Endothelial Cells Hypertension, October 1, 2007; 50(4): 643 - 651. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. A. Rogers, W. M. Chilian, I. N. Bratz, R. M. Bryan Jr., and G. M. Dick H2O2 activates redox- and 4-aminopyridine-sensitive Kv channels in coronary vascular smooth muscle Am J Physiol Heart Circ Physiol, March 1, 2007; 292(3): H1404 - H1411. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. A. Rogers, G. M. Dick, J. D. Knudson, M. Focardi, I. N. Bratz, A. N. Swafford Jr., S.-i. Saitoh, J. D. Tune, and W. M. Chilian H2O2-induced redox-sensitive coronary vasodilation is mediated by 4-aminopyridine-sensitive K+ channels Am J Physiol Heart Circ Physiol, November 1, 2006; 291(5): H2473 - H2482. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 N. Ardanaz and P. J. Pagano Hydrogen peroxide as a paracrine vascular mediator: regulation and signaling leading to dysfunction. Experimental Biology and Medicine, March 1, 2006; 231(3): 237 - 251. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. Xu, X. Bian, S. W. Watts, and A. Hlavacova Activation of Vascular BK Channel by Tempol in DOCA-Salt Hypertensive Rats Hypertension, November 1, 2005; 46(5): 1154 - 1162. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. D. Denson, J. Li, X. Wang, and D. C. Eaton Activation of BK Channels in GH3 Cells by a c-PLA2-Dependent G-Protein Signaling Pathway J Neurophysiol, June 1, 2005; 93(6): 3146 - 3156. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. C. Santarelli, J. Chen, S. H. Heinemann, and T. Hoshi The {beta}1 Subunit Enhances Oxidative Regulation of Large-Conductance Calcium-activated K+ Channels J. Gen. Physiol., September 27, 2004; 124(4): 357 - 370. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. Cseko, Z. Bagi, and A. Koller Biphasic effect of hydrogen peroxide on skeletal muscle arteriolar tone via activation of endothelial and smooth muscle signaling pathways J Appl Physiol, September 1, 2004; 97(3): 1130 - 1137. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. Thengchaisri and L. Kuo Hydrogen peroxide induces endothelium-dependent and -independent coronary arteriolar dilation: role of cyclooxygenase and potassium channels Am J Physiol Heart Circ Physiol, December 1, 2003; 285(6): H2255 - H2263. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. L. Clarke, S. Petrou, J. V. Walsh Jr., and J. J. Singer Modulation of BKCa channel activity by fatty acids: structural requirements and mechanism of action Am J Physiol Cell Physiol, November 1, 2002; 283(5): C1441 - C1453. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
W. B. Campbell and D. R. Harder Prologue: EDHF-what is it? Am J Physiol Heart Circ Physiol, June 1, 2001; 280(6): H2413 - H2416. [Full Text] [PDF]
|
|
|
|
|
|
C. A. Hamilton, A. R. McPhaden, G. Berg, V. Pathi, and A. F. Dominiczak Is hydrogen peroxide an EDHF in human radial arteries? Am J Physiol Heart Circ Physiol, June 1, 2001; 280(6): H2451 - H2455. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
