| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Department of Pharmacology, University of Vermont, Burlington, Vermont 05405
The goal of the present study was to test
the hypothesis that local Ca2+ release events
(Ca2+ sparks) deliver high local Ca2+
concentration to activate nearby Ca2+-sensitive
K+ (BK) channels in the cell membrane of arterial smooth
muscle cells. Ca2+ sparks and BK channels were examined in
isolated myocytes from rat cerebral arteries with laser scanning
confocal microscopy and patch-clamp techniques. BK channels had an
apparent dissociation constant for Ca2+ of 19 µM and a
Hill coefficient of 2.9 at 
40 mV. At near-physiological intracellular
Ca2+ concentration ([Ca2+]i; 100 nM) and membrane potential (40 mV), the open probability of a single
BK channel was low (1.2 × 10
6). A Ca2+
spark increased BK channel activity to 18. Assuming that 1-100% of the BK channels are activated by a single Ca2+ spark, BK
channel activity increases 6 × 105-fold to 6 × 103-fold, which corresponds to ~30 µM to 4 µM spark
Ca2+ concentration.
1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid
acetoxymethyl ester caused the disappearance of all Ca2+
sparks while leaving the transient BK currents unchanged. Our results
support the idea that Ca2+ spark sites are in close
proximity to the BK channels and that local
[Ca2+]i reaches micromolar levels to activate
BK channels.
ryanodine receptor; local calcium release; BK potassium channel
This article has been cited by other articles:
|
|
 |
|
  A. M. Dopico and D. M. Lovinger Acute Alcohol Action and Desensitization of Ligand-Gated Ion Channels Pharmacol. Rev., March 1, 2009; 61(1): 98 - 114. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. Csanady and B. Torocsik Four Ca2+ Ions Activate TRPM2 Channels by Binding in Deep Crevices near the Pore but Intracellularly of the Gate J. Gen. Physiol., February 1, 2009; 133(2): 189 - 203. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. N. Bukiya, J. McMillan, A. L. Parrill, and A. M. Dopico Structural determinants of monohydroxylated bile acids to activate {beta}1 subunit-containing BK channels J. Lipid Res., November 1, 2008; 49(11): 2441 - 2451. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. Cheng and W. J. Lederer Calcium Sparks Physiol Rev, October 1, 2008; 88(4): 1491 - 1545. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. Tazzeo, Y. Zhang, S. Keshavjee, and L. J. Janssen Ryanodine receptors decant internal Ca2+ store in human and bovine airway smooth muscle Eur. Respir. J., August 1, 2008; 32(2): 275 - 284. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. Francis, S. Glaser, S. DeMorrow, E. Gaudio, Y. Ueno, J. Venter, D. Dostal, P. Onori, A. Franchitto, M. Marzioni, et al. Small mouse cholangiocytes proliferate in response to H1 histamine receptor stimulation by activation of the IP3/CaMK I/CREB pathway Am J Physiol Cell Physiol, August 1, 2008; 295(2): C499 - C513. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. Bao, L. M. Lifshitz, R. A. Tuft, K. Bellve, K. E. Fogarty, and R. ZhuGe A Close Association of RyRs with Highly Dense Clusters of Ca2+-activated Cl- Channels Underlies the Activation of STICs by Ca2+ Sparks in Mouse Airway Smooth Muscle J. Gen. Physiol., July 1, 2008; 132(1): 145 - 160. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Li, Q. Xi, E. S. Umstot, L. Bellner, M. L. Schwartzman, J. H. Jaggar, and C. W. Leffler Astrocyte-Derived CO Is a Diffusible Messenger That Mediates Glutamate-Induced Cerebral Arteriolar Dilation by Activating Smooth Muscle Cell KCa Channels Circ. Res., February 1, 2008; 102(2): 234 - 241. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. Essin, A. Welling, F. Hofmann, F. C. Luft, M. Gollasch, and S. Moosmang Indirect coupling between Cav1.2 channels and ryanodine receptors to generate Ca2+ sparks in murine arterial smooth muscle cells J. Physiol., October 1, 2007; 584(1): 205 - 219. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. N. Bukiya, J. Liu, L. Toro, and A. M. Dopico beta1 (KCNMB1) Subunits Mediate Lithocholate Activation of Large-Conductance Ca2+-Activated K+ Channels and Dilation in Small, Resistance-Size Arteries Mol. Pharmacol., August 1, 2007; 72(2): 359 - 369. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. Zhao, A. Adebiyi, Q. Xi, and J. H. Jaggar Hypoxia reduces KCa channel activity by inducing Ca2+ spark uncoupling in cerebral artery smooth muscle cells Am J Physiol Cell Physiol, June 1, 2007; 292(6): C2122 - C2128. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Kim and B. A. Perrino CaM kinase II activation and phospholamban phosphorylation by SNP in murine gastric antrum smooth muscles Am J Physiol Gastrointest Liver Physiol, April 1, 2007; 292(4): G1045 - G1054. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. K. Isacson, Q. Lu, R. H. Karas, and D. H. Cox RACK1 is a BKCa channel binding protein Am J Physiol Cell Physiol, April 1, 2007; 292(4): C1459 - C1466. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Brown, T. Cornwell, I. Korniyenko, V. Solodushko, C. T. Bond, J. P. Adelman, and M. S. Taylor Myometrial expression of small conductance Ca2+-activated K+ channels depresses phasic uterine contraction Am J Physiol Cell Physiol, February 1, 2007; 292(2): C832 - C840. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. V. Straub, A. D. Bonev, M. K. Wilkerson, and M. T. Nelson Dynamic Inositol Trisphosphate-mediated Calcium Signals within Astrocytic Endfeet Underlie Vasodilation of Cerebral Arterioles J. Gen. Physiol., December 1, 2006; 128(6): 659 - 669. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Li, A. Adebiyi, C. W. Leffler, and J. H. Jaggar KCa channel insensitivity to Ca2+ sparks underlies fractional uncoupling in newborn cerebral artery smooth muscle cells Am J Physiol Heart Circ Physiol, September 1, 2006; 291(3): H1118 - H1125. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. T. Lin, D. A. Hessinger, W. J. Pearce, and L. D. Longo Modulation of BK channel calcium affinity by differential phosphorylation in developing ovine basilar artery myocytes Am J Physiol Heart Circ Physiol, August 1, 2006; 291(2): H732 - H740. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Kim, I. S. Han, S. D. Koh, and B. A. Perrino Roles of CaM kinase II and phospholamban in SNP-induced relaxation of murine gastric fundus smooth muscles Am J Physiol Cell Physiol, August 1, 2006; 291(2): C337 - C347. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. M. Hagen, O. Bayguinov, and K. M. Sanders VIP and PACAP regulate localized Ca2+ transients via cAMP-dependent mechanism Am J Physiol Cell Physiol, August 1, 2006; 291(2): C375 - C385. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. V. Straub and M. T. Nelson Molecular Coding of Kv1 Channels to Oppose Myogenic Constriction Circ. Res., July 7, 2006; 99(1): 13 - 14. [Full Text] [PDF]
|
|
|
|
|
|
X. Cheng and J. H. Jaggar Genetic ablation of caveolin-1 modifies Ca2+ spark coupling in murine arterial smooth muscle cells Am J Physiol Heart Circ Physiol, June 1, 2006; 290(6): H2309 - H2319. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Y. Cheranov and J. H. Jaggar TNF-{alpha} dilates cerebral arteries via NAD(P)H oxidase-dependent Ca2+ spark activation Am J Physiol Cell Physiol, April 1, 2006; 290(4): C964 - C971. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. P. Burnham, I. T. Johnson, and A. H. Weston Reduced Ca2+-dependent activation of large-conductance Ca2+-activated K+ channels from arteries of Type 2 diabetic Zucker diabetic fatty rats Am J Physiol Heart Circ Physiol, April 1, 2006; 290(4): H1520 - H1527. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. C. Amberg, M. F. Navedo, and L. F. Santana On the Loose: Uncaging Ca2+-induced Ca2+ Release in Smooth Muscle J. Gen. Physiol., February 27, 2006; 127(3): 221 - 223. [Full Text] [PDF]
|
|
|
|
|
|
R. E Haddock and C. E Hill Rhythmicity in arterial smooth muscle J. Physiol., August 1, 2005; 566(3): 645 - 656. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Kim, S. Y. Cho, I. S. Han, S. D. Koh, and B. A. Perrino CaM kinase II and phospholamban contribute to caffeine-induced relaxation of murine gastric fundus smooth muscle Am J Physiol Cell Physiol, June 1, 2005; 288(6): C1202 - C1210. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Ahmed, C. M. Waters, C. W. Leffler, and J. H. Jaggar Ionic mechanisms mediating the myogenic response in newborn porcine cerebral arteries Am J Physiol Heart Circ Physiol, November 1, 2004; 287(5): H2061 - H2069. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. Barkoudah, J. H. Jaggar, and C. W. Leffler The permissive role of endothelial NO in CO-induced cerebrovascular dilation Am J Physiol Heart Circ Physiol, October 1, 2004; 287(4): H1459 - H1465. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. Csanady and V. Adam-Vizi Antagonistic Regulation of Native Ca2+- and ATP-sensitive Cation Channels in Brain Capillaries by Nucleotides and Decavanadate J. Gen. Physiol., June 1, 2004; 123(6): 743 - 757. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Q. Xi, D. Tcheranova, H. Parfenova, B. Horowitz, C. W. Leffler, and J. H. Jaggar Carbon monoxide activates KCa channels in newborn arteriole smooth muscle cells by increasing apparent Ca2+ sensitivity of {alpha}-subunits Am J Physiol Heart Circ Physiol, February 1, 2004; 286(2): H610 - H618. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 W.-M. Zhang, K.-P. Yip, M.-J. Lin, L. A. Shimoda, W.-H. Li, and J. S. K. Sham ET-1 activates Ca2+ sparks in PASMC: local Ca2+ signaling between inositol trisphosphate and ryanodine receptors Am J Physiol Lung Cell Mol Physiol, September 1, 2003; 285(3): L680 - L690. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Han, N. Kim, H. Joo, and E. Kim Ketamine blocks Ca2+-activated K+ channels in rabbit cerebral arterial smooth muscle cells Am J Physiol Heart Circ Physiol, August 7, 2003; 285(3): H1347 - H1355. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. T. Lin, D. A. Hessinger, W. J. Pearce, and L. D. Longo Developmental differences in Ca2+-activated K+ channel activity in ovine basilar artery Am J Physiol Heart Circ Physiol, July 11, 2003; 285(2): H701 - H709. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. Malli, M. Frieden, K. Osibow, and W. F. Graier Mitochondria Efficiently Buffer Subplasmalemmal Ca2+ Elevation during Agonist Stimulation J. Biol. Chem., March 14, 2003; 278(12): 10807 - 10815. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R E Haddock and C E Hill Differential activation of ion channels by inositol 1,4,5-trisphosphate (IP3)- and ryanodine-sensitive calcium stores in rat basilar artery vasomotion J. Physiol., December 1, 2002; 545(2): 615 - 627. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Y Cheranov and J. H Jaggar Sarcoplasmic reticulum calcium load regulates rat arterial smooth muscle calcium sparks and transient KCa currents J. Physiol., October 1, 2002; 544(1): 71 - 84. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. M Herrera and M. T Nelson Differential regulation of SK and BK channels by Ca2+ signals from Ca2+ channels and ryanodine receptors in guinea-pig urinary bladder myocytes J. Physiol., June 1, 2002; 541(2): 483 - 492. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C.-H. Lee, D. Poburko, K.-H. Kuo, C. Y. Seow, and C. van Breemen Ca2+ oscillations, gradients, and homeostasis in vascular smooth muscle Am J Physiol Heart Circ Physiol, May 1, 2002; 282(5): H1571 - H1583. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
