| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Exocytotic events and changes of cell volume in mucous cells from guinea-pig antrum were examined by video-enhanced optical microscopy.
Acetylcholine (ACh) evoked exocytotic events following cell shrinkage, the frequency and extent of which depended on the ACh concentration. ACh actions were mimicked by ionomycin and thapsigargin, and inhibited by Ca2+-free solution and Ca2+ channel blockers (Ni2+, Cd2+ and nifedipine). Application of 100 µM W-7, a calmodulin inhibitor, also inhibited the ACh-induced exocytotic events. These results indicate that ACh actions are mediated by intracellular Ca2+ concentration ([Ca2+]i) in antral mucous cells.
The effects of ion channel blockers on exocytotic events and cell shrinkage evoked by ACh were examined. Inhibition of KCl release (quinine, Ba2+, NPPB or KCl solution) suppressed both the exocytotic events and cell shrinkage evoked by ACh.
Bumetanide (inhibition of NaCl entry) or Cl--free solution (increasing Cl- release and inhibition of NaCl entry) evoked exocytotic events following cell shrinkage in unstimulated antral mucous cells and caused further cell shrinkage and increases in the frequency of exocytotic events in ACh-stimulated cells. However, Cl--free solution did not evoke exocytotic events in unstimulated cells in the absence of extracellular Ca2+, although cell shrinkage occurred.
To examine the effects of cell volume on ACh-evoked exocytosis, the cell volume was altered by increasing the extracellular K+ concentration. The results showed that cell shrinkage increases the frequency of ACh-evoked exocytotic events and cell swelling decreases them.
Osmotic shrinkage or swelling caused the frequency of ACh-evoked exocytotic events to increase. This suggests that the effects of cell volume on ACh-evoked exocytosis under anisosmotic conditions may not be the same as those under isosmotic conditions.
In antral mucous cells, Ca2+-regulated exocytosis is modulated by cell shrinkage under isosmotic conditions.
This article has been cited by other articles:
|
|
 |
|
  C. Shimamoto, E. Umegaki, K.-i. Katsu, M. Kato, S. Fujiwara, T. Kubota, and T. Nakahari [Cl ]i modulation of Ca2+-regulated exocytosis in ACh-stimulated antral mucous cells of guinea pig Am J Physiol Gastrointest Liver Physiol, October 1, 2007; 293(4): G824 - G837. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. Shimamoto, Y. Nakanishi, K.-i. Katsu, T. Nakano, T. Kubota, H. Mori, and T. Nakahari Prostaglandin E2 release in gastric antral mucosa of guinea-pigs: basal PGE2 release by cyclo-oxygenase 2 and ACh-stimulated PGE2 release by cyclo-oxygenase 1 Exp Physiol, November 1, 2006; 91(6): 1015 - 1024. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. H. Saad, C. Shimamoto, T. Nakahari, S. Fujiwara, K.-i. Katsu, and Y. Marunaka cGMP modulation of ACh-stimulated exocytosis in guinea pig antral mucous cells Am J Physiol Gastrointest Liver Physiol, June 1, 2006; 290(6): G1138 - G1148. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Fujiwara, C. Shimamoto, Y. Nakanishi, K.-i. Katsu, M. Kato, and T. Nakahari Enhancement of Ca2+-regulated exocytosis by indomethacin in guinea-pig antral mucous cells: arachidonic acid accumulation Exp Physiol, January 1, 2006; 91(1): 249 - 259. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Hayashi, M. Kawakami, S. Sasaki, T. Katsumata, H. Mori, H. Yoshida, and T. Nakahari ATP regulation of ciliary beat frequency in rat tracheal and distal airway epithelium Exp Physiol, July 1, 2005; 90(4): 535 - 544. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. Murao, A. Shimizu, K. Hosoi, A. Iwagaki, K.-Y. Min, G.-i. Kishima, T. Hanafusa, T. Kubota, M. Kato, H. Yoshida, et al. Cell shrinkage evoked by Ca2+-free solution in rat alveolar type II cells: Ca2+ regulation of Na+-H+ exchange Exp Physiol, March 1, 2005; 90(2): 203 - 213. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. Shimamoto, S. Fujiwara, M. Kato, S. Ito, K.-i. Katsu, H. Mori, and T. Nakahari Inhibition of ACh-stimulated exocytosis by NSAIDs in guinea pig antral mucous cells: autocrine regulation of mucin secretion by PGE2 Am J Physiol Gastrointest Liver Physiol, January 1, 2005; 288(1): G39 - G47. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. Hosoi, K.-Y. Min, A. Iwagaki, H. Murao, T. Hanafusa, C. Shimamoto, K.-i. Katsu, M. Kato, S. Fujiwara, and T. Nakahari Delayed shrinkage triggered by the Na+-K+ pump in terbutaline-stimulated rat alveolar type II cells Exp Physiol, July 1, 2004; 89(4): 373 - 385. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. Shiima-Kinoshita, K.-Y. Min, T. Hanafusa, H. Mori, and T. Nakahari {beta}2-adrenergic regulation of ciliary beat frequency in rat bronchiolar epithelium: potentiation by isosmotic cell shrinkage J. Physiol., January 15, 2004; 554(2): 403 - 416. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Nakahari, S. Fujiwara, C. Shimamoto, K. Kojima, K.-I. Katsu, and Y. Imai cAMP modulation of Ca2+-regulated exocytosis in ACh-stimulated antral mucous cells of guinea pig Am J Physiol Gastrointest Liver Physiol, May 1, 2002; 282(5): G844 - G856. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. Su, D. B. Kintner, and D. Sun Contribution of Na+-K+-Cl- cotransporter to high-[K+]o- induced swelling and EAA release in astrocytes Am J Physiol Cell Physiol, May 1, 2002; 282(5): C1136 - C1146. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
