View : 13 Download: 0

Protein kinase C mediates the desensitization of CCh-activated nonselective cationic current in guinea-pig gastric myocytes

Title
Protein kinase C mediates the desensitization of CCh-activated nonselective cationic current in guinea-pig gastric myocytes
Authors
Kim Y.C.Kim S.J.Sim J.H.Jun J.Y.Kang T.M.Suh S.H.So I.Kim K.W.
Ewha Authors
서석효
SCOPUS Author ID
서석효scopus
Issue Date
1998
Journal Title
Pflugers Archiv European Journal of Physiology
ISSN
0031-6768JCR Link
Citation
vol. 436, no. 1, pp. 1 - 8
Indexed
SCI; SCIE; SCOPUS WOS scopus
Abstract
The possibility of the protein kinase C (PKC) pathway being a mechanism underlying the desensitization of carbachol- (CCh-)activated nonselective cationic current (I(CCh)) was investigated in a study of guinea-pig gastric myocytes. Using the conventional whole-cell patch-clamp technique with symmetrical CsCl-rich solution in pipette and bath, I(CCh) was induced by bath application of 50 μM CCh. With 0.5 mM EGTA [ethyleneglycol-bis(β-aminoethyl ether)-N,N,N',N'-tetraacetic acid] in the pipette solution (0.5 mM [EGTA](i)), I(CCh) decayed spontaneously (desensitization of I(CCh)) to around 20% within 10 min. Desensitization of I(CCh) was significantly attenuated with 2 mM [EGTA](i). At a concentration of 20 μM OAG (1-oleoyl-2-acetyl-sn-glycerol), a PKC activator, inhibited I(CCh) at 0.5 mM [EGTA](i) but far less at 2 mM [EGTA](i) (18% and 81% of control, respectively). The same cationic current induced by intracellular guanosine-5'-O-(3-thiotriphosphate) (GTP[γ-S]) was not inhibited by OAG with 0.5 mM [EGTA](i). The pretreatment of gastric myocytes with PKC inhibitors, either 1 μM chelerythrine or 1 μM peptide inhibitor, attenuated the desensitization of I(CCh). [Ca2+](i) was also measured by single cell microfluorometry using fura-2. Under CCh stimulation with 2 mM [EGTA](i), [Ca2+](i) did not increase above 100 nM while it increased to around 260 nM with 0.5 mM [EGTA](i). These results suggest that the desensitization of I(CCh) is partly due to the Ca2+-dependent PKC pathway in guinea-pig gastric myocytes.
DOI
10.1007/s004240050597
Appears in Collections:
의학전문대학원 > 의학과 > Journal papers
Files in This Item:
There are no files associated with this item.
Export
RIS (EndNote)
XLS (Excel)
XML


qrcode

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

BROWSE