Document Detail


Protein tyrosine kinase-dependent modulation of isoflurane effects on cardiac sarcolemmal K(ATP) channel.
MedLine Citation:
PMID:  12411806     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
BACKGROUND: Cardiac adenosine triphosphate-sensitive potassium (K(ATP)) channels and protein tyrosine kinases (PTKs) are mediators of ischemic preconditioning, but the interaction of both and a role in myocardial protection afforded by volatile anesthetics have not been defined. METHODS: Whole cell and single channel patch clamp techniques were used to investigate the effects of isoflurane and the PTK inhibitor genistein on the cardiac sarcolemmal K(ATP) channel in acutely dissociated guinea pig ventricular myocytes. RESULTS: At 0.5 mm internal ATP, genistein (50 microm) elicited whole cell K(ATP) current (22.5 +/- 7.9 pA/pF). Genistein effects were concentration-dependent, with an EC50 of 32.3 +/- 1.4 microm. Another PTK inhibitor, tyrphostin B42, had a similar effect. The inactive analog of genistein, daidzein (50 microm), did not elicit K(ATP) current. Isoflurane (0.5 mm) increased genistein (35 microm)-activated whole cell K(ATP) current from 14.5 +/- 3.1 to 32.5 +/- 6.6 pA/pF. Stimulation of receptor PTKs with epidermal growth factor, nerve growth factor, or insulin attenuated genistein and isoflurane effects, and the protein tyrosine phosphatase inhibitor orthovanadate (1 mm) prevented their actions on K(ATP) current. In excised inside-out membrane patches, and at fixed 0.2 mm internal ATP, genistein (50 microm) increased channel open probability from 0.053 +/- 0.016 to 0.183 +/- 0.039, but isoflurane failed to further increase open probability (0.162 +/- 0.051) of genistein-activated channels. However, applied in the presence of genistein and protein tyrosine phosphatase 1B (1 microg/ml), isoflurane significantly increased open probability to 0.473 +/- 0.114. CONCLUSIONS: These results suggest that the PTK-protein tyrosine phosphatase signaling pathway may be one of the regulators of cardiac sarcolemmal K(ATP) channel and may play a role in modulating its responsiveness to isoflurane. Relative importance of this modulation for cardioprotection by volatile anesthetics remains to be established.
Authors:
Anna Stadnicka; Wai-Meng Kwok; David C Warltier; Zeljko J Bosnjak
Related Documents :
3593316 - Structure and function of red cell cytoskeleton.
15800986 - Adenosine 5'triphosphate transport and accumulation during the cold preservation of rat...
7520086 - Extracellular atp-induced currents in astrocytes: involvement of a cation channel.
10755546 - Mycophenolic acid-induced gtp depletion also affects atp and pyrimidine synthesis in mi...
21170146 - Refilling intracellular calcium stores.
10742306 - Effects of inhibitors of small- and intermediate-conductance calcium-activated potassiu...
Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Anesthesiology     Volume:  97     ISSN:  0003-3022     ISO Abbreviation:  Anesthesiology     Publication Date:  2002 Nov 
Date Detail:
Created Date:  2002-11-04     Completed Date:  2002-11-27     Revised Date:  2009-11-19    
Medline Journal Info:
Nlm Unique ID:  1300217     Medline TA:  Anesthesiology     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1198-208     Citation Subset:  AIM; IM    
Affiliation:
Department of Anesthesiology, Medical College of Wisconsin, Milwaukee 53226, USA. astadnic@mcw.edu
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Adenosine Triphosphate / pharmacology*
Anesthetics, Inhalation / pharmacology*
Animals
Drug Synergism
Female
Genistein / pharmacology
Guinea Pigs
Heart / drug effects*
Isoflurane / pharmacology*
Male
Potassium Channels / drug effects*
Protein-Tyrosine Kinases / physiology*
Sarcolemma / drug effects
Grant Support
ID/Acronym/Agency:
HL34708-14/HL/NHLBI NIH HHS
Chemical
Reg. No./Substance:
0/Anesthetics, Inhalation; 0/Potassium Channels; 26675-46-7/Isoflurane; 446-72-0/Genistein; 56-65-5/Adenosine Triphosphate; EC 2.7.10.1/Protein-Tyrosine Kinases

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Mild hypothermia has minimal effects on the tolerance to severe progressive normovolemic anemia in S...
Next Document:  Biphasic effects of isoflurane on the cardiac action potential: an ionic basis for anesthetic-induce...