J Physiol Wellcome Trust-funded researchers
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
 QUICK SEARCH:   [advanced]


     


J Physiol Vol 225, Issue 3 pp 693-703
Copyright © 1972 by The Physiological Society
This Article
Right arrow Full Text (PDF)
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Tomita, T.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Tomita, T.

Conductance change during the inhibitory potential in the guinea-pig taenia coli

T. Tomita

1. Effects of membrane polarization and of reduction in external K and Cl concentration on the inhibitory potential were investigated in the guinea-pig taenia coli.

2. Depolarization of the membrane increased the inhibitory potential while hyperpolarization decreased it. The relationship between the degree of membrane polarization and the amplitude of inhibitory potential was linear. The inhibitory potential was abolished or slightly reversed in polarity, when the membrane was hyperpolarized by 25-40 mV in different preparations.

3. Removal of external K ion depolarized the membrane for about 5 min and increased the inhibitory potential more than could be accounted for by the depolarization. Readmission of K transiently hyperpolarized the membrane, probably due to an activation of the Na-K pump, and reduced the inhibitory potential, but no reversal of polarity in the inhibitory potential was observed during this hyperpolarizing phase.

4. The membrane was transiently depolarized when the external Cl concentration was reduced by substituting with isethionate. Hyperpolarization was produced by restoring the external Cl concentration to normal. Changes in the amplitude of inhibitory potentials during alterations in Cl concentration occurred as expected from the shift of the membrane potential.

5. From the results, it is concluded that the membrane conductance is increased during the inhibitory potential, and that an increase in the K permeability is the main factor for hyperpolarization of the membrane.




This article has been cited by other articles:


Home page
Am. J. Physiol. Gastrointest. Liver Physiol.Home page
R. K. Goyal and X. D. He
Evidence for NO · redox form of nitric oxide as nitrergic inhibitory neurotransmitter in gut
Am J Physiol Gastrointest Liver Physiol, November 1, 1998; 275(5): G1185 - G1192.
[Abstract] [Full Text] [PDF]


Home page
Physiol. Rev.Home page
H. KURIYAMA, K. KITAMURA, T. ITOH, and R. INOUE
Physiological Features of Visceral Smooth Muscle Cells, With Special Reference to Receptors and Ion Channels
Physiol Rev, July 1, 1998; 78(3): 811 - 920.
[Abstract] [Full Text] [PDF]


Home page
Am. J. Physiol. Cell Physiol.Home page
S. D. Koh, G. M. Dick, and K. M. Sanders
Small-conductance Ca2+-dependent K+ channels activated by ATP in murine colonic smooth muscle
Am J Physiol Cell Physiol, December 1, 1997; 273(6): C2010 - C2021.
[Abstract] [Full Text] [PDF]




HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1972 The Physiological Society.