| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, Nevada 89557
The patch-clamp
technique was used to determine the ionic conductances activated by ATP
in murine colonic smooth muscle cells. Extracellular ATP, UTP, and
2-methylthioadenosine 5'-triphosphate (2-MeS-ATP) increased
outward currents in cells with amphotericin B-perforated patches. ATP
(0.5-1 mM) did not affect whole cell currents of cells dialyzed
with solutions containing ethylene glycol-bis(
-aminoethyl
ether)-N,N,N',N'-tetraacetic
acid. Apamin (3 × 10
7
M) reduced the outward current activated by ATP by 32 ± 5%. Single channel recordings from cell-attached patches showed that ATP, UTP, and
2-MeS-ATP increased the open probability of small-conductance, Ca2+-dependent
K+ channels with a slope
conductance of 5.3 ± 0.02 pS. Caffeine (500 µM) enhanced the open
probability of the small-conductance K+ channels, and ATP had no effect
after caffeine. Pyridoxal phosphate 6-azophenyl-2',4'-disulfonic acid tetrasodium (PPADS,
104 M), a nonselective
P2 receptor antagonist, prevented
the increase in open probability caused by ATP and 2-MeS-ATP. PPADS had
no effect on the response to caffeine. ATP-induced hyperpolarization in
the murine colon may be mediated by
P2y-induced release of Ca2+ from intracellular stores and
activation of the 5.3-pS
Ca2+-activated
K+ channels.
ion channels; apamin; caffeine; purinergic receptors; enteric inhibitory neurotransmission; gastrointestinal motility
This article has been cited by other articles:
|
|
 |
|
  G.-D. Wang, X.-Y. Wang, H.-Z. Hu, S. Liu, N. Gao, X. Fang, Y. Xia, and J. D. Wood Inhibitory neuromuscular transmission mediated by the P2Y1 purinergic receptor in guinea pig small intestine Am J Physiol Gastrointest Liver Physiol, June 1, 2007; 292(6): G1483 - G1489. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. P. Monaghan, S. D. Koh, S. Ro, J. Yeom, B. Horowitz, and K. M. Sanders Nucleotide regulation of the voltage-dependent nonselective cation conductance in murine colonic myocytes Am J Physiol Cell Physiol, November 1, 2006; 291(5): C985 - C994. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. Takeda, S. M. Ward, K. M. Sanders, and S. D. Koh Effects of the gap junction blocker glycyrrhetinic acid on gastrointestinal smooth muscle cells Am J Physiol Gastrointest Liver Physiol, April 1, 2005; 288(4): G832 - G841. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. A. Baker, V. Mutafova-Yambolieva, K. Monaghan, B. Horowitz, K. M. Sanders, and S. D. Koh Mechanism of active repolarization of inhibitory junction potential in murine colon Am J Physiol Gastrointest Liver Physiol, November 1, 2003; 285(5): G813 - G821. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Fujita, T. Takeuchi, N. Saitoh, J. Hanai, and F. Hata Expression of Ca2+-activated K+ channels, SK3, in the interstitial cells of Cajal in the gastrointestinal tract Am J Physiol Cell Physiol, November 1, 2001; 281(5): C1727 - C1733. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Ro, W. J. Hatton, S. D. Koh, and B. Horowitz Molecular properties of small-conductance Ca2+-activated K+ channels expressed in murine colonic smooth muscle Am J Physiol Gastrointest Liver Physiol, October 1, 2001; 281(4): G964 - G973. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
O. Bayguinov, B. Hagen, and K. M. Sanders Muscarinic stimulation increases basal Ca2+ and inhibits spontaneous Ca2+ transients in murine colonic myocytes Am J Physiol Cell Physiol, March 1, 2001; 280(3): C689 - C700. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. N. Holm, A. Rich, M. G. Sarr, and G. Farrugia Whole cell current and membrane potential regulation by a human smooth muscle mechanosensitive calcium channel Am J Physiol Gastrointest Liver Physiol, December 1, 2000; 279(6): G1155 - G1161. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K M Sanders Postjunctional electrical mechanisms of enteric neurotransmission Gut, December 1, 2000; 47(90004): iv23 - 25. [Full Text] [PDF]
|
|
|
|
 |
|
 G. M. Herrera, T. J. Heppner, and M. T. Nelson Regulation of urinary bladder smooth muscle contractions by ryanodine receptors and BK and SK channels Am J Physiol Regulatory Integrative Comp Physiol, July 1, 2000; 279(1): R60 - R68. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
O. Bayguinov, B. Hagen, A. D. Bonev, M. T. Nelson, and K. M. Sanders Intracellular calcium events activated by ATP in murine colonic myocytes Am J Physiol Cell Physiol, July 1, 2000; 279(1): C126 - C135. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. H. Jaggar, V. A. Porter, W. J. Lederer, and M. T. Nelson Calcium sparks in smooth muscle Am J Physiol Cell Physiol, February 1, 2000; 278(2): C235 - C256. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
I. D. Kong, S. D. Koh, and K. M. Sanders Purinergic activation of spontaneous transient outward currents in guinea pig taenia colonic myocytes Am J Physiol Cell Physiol, February 1, 2000; 278(2): C352 - C362. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Epperson, H. P. Bonner, S. M. Ward, W. J. Hatton, K. K. Bradley, M. E. Bradley, J. S. Trimmer, and B. Horowitz Molecular diversity of KV alpha - and beta -subunit expression in canine gastrointestinal smooth muscles Am J Physiol Gastrointest Liver Physiol, July 1, 1999; 277(1): G127 - G136. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. Xue, G. Farrugia, M. G. Sarr, and J. H. Szurszewski ATP is a mediator of the fast inhibitory junction potential in human jejunal circular smooth muscle Am J Physiol Gastrointest Liver Physiol, June 1, 1999; 276(6): G1373 - G1379. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. R. Hurley, H. G. Preiksaitis, and S. M. Sims Characterization and regulation of Ca2+-dependent K+ channels in human esophageal smooth muscle Am J Physiol Gastrointest Liver Physiol, April 1, 1999; 276(4): G843 - G852. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. M. Sanders IV. Neural regulation of gastrointestinal smooth muscle Am J Physiol Gastrointest Liver Physiol, July 1, 1998; 275(1): G1 - G7. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. M. Dick and K. M. Sanders (Xeno)estrogen Sensitivity of Smooth Muscle BK Channels Conferred by the Regulatory beta 1 Subunit. A STUDY OF beta 1 KNOCKOUT MICE J. Biol. Chem., November 21, 2001; 276(48): 44835 - 44840. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
