scholarly journals Protein kinase C modulation of recombinant ATP‐sensitive K + channels composed of Kir6.1 and/or Kir6.2 expressed with SUR2B

2002 ◽  
Vol 541 (1) ◽  
pp. 65-80 ◽  
Author(s):  
Kevin S. Thorneloe ◽  
Yoshiaki Maruyama ◽  
A. Todd Malcolm ◽  
Peter E. Light ◽  
Michael P. Walsh ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
K Channels ◽  
Kinase C

Protein Kinase C–Induced Changes in the Stoichiometry of ATP Binding Activate Cardiac ATP-Sensitive K+Channels

1996 ◽  
Vol 79 (3) ◽  
pp. 399-406 ◽  
Author(s):  
Peter E. Light ◽  
Aftab A. Sabir ◽  
Bruce G. Allen ◽  
Michael P. Walsh ◽  
Robert J. French
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Atp Binding ◽  
K Channels ◽  
Kinase C ◽  
Induced Changes

Arachidonic acid enhances contraction and intracellular Ca2+ transients in individual rat ventricular myocytes

1997 ◽  
Vol 272 (1) ◽  
pp. H350-H359 ◽  
Author(s):  
D. S. Damron ◽  
B. A. Summers
Keyword(s):  
Arachidonic Acid ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Cardiac Muscle ◽  
Ventricular Myocytes ◽  
Contractile Function ◽  
Receptor Activation ◽  
K Channels ◽  
Rat Ventricular Myocytes ◽  
Kinase C

Modulation of intracellular free Ca2+ concentration ([Ca2+]i) by inotropic stimuli alters contractility in cardiac muscle. Arachidonic acid (AA), a precursor for eicosanoid formation, is released in response to receptor activation and myocardial ischemia and has been demonstrated to alter K+ and Ca2+ channel activity. We investigated the effects of AA on contractility by simultaneously measuring [Ca2+]i and shortening in single field-stimulated rat ventricular myocytes. [Ca2+]i transients were measured using fura 2, and myocyte shortening was assessed using video edge detection. AA stimulated a doubling in the amplitude of the [Ca2+]i transient and a twofold increase in myocyte shortening. In addition, AA stimulated a 30% increase in the time to 50% diastolic [Ca2+]i and a 35% increase in the time to 50% relengthening. These effects of AA were mediated by AA itself (56 +/- 5%) and by cyclooxygenase metabolites. Pretreatment with the protein kinase C inhibitors staurosporine and chelerythrine nearly abolished (> 90% inhibition) these AA-induced effects. Inhibition of voltagegated K+ channels with 4-aminopyridine mimicked the effects of AA. Addition of AA to the 4-aminopyridine-treated myocyte had no additional effect on parameters of contractile function. These data indicate that AA alters the amplitude and duration of Ca2- transients and myocyte shortening via protein kinase C-dependent inhibition of voltage-gated K+ channels. Release of AA by phospholipases in response to receptor activation by endogenous mediators or pathological stimuli may be involved in mediating inotropic responses in cardiac muscle.

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