JOURNAL HOME CME HOME THIS MONTH PAST ISSUES ETOC COLLECTIONS
AUTHORS REVIEWERS EDITORIAL BOARD FEEDBACK RSS HELP
A&A International Anesthesia Research Society
QUICK SEARCH:   [advanced]


     

This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a colleague
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
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 ISI Web of Science (2)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Kohro, S.
Right arrow Articles by Bosnjak, Z. J.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Kohro, S.
Right arrow Articles by Bosnjak, Z. J.
Related Collections
Right arrow Heart
Right arrow Pharmacology

Anesth Analg 2004;99:1316-1322
© 2004 International Anesthesia Research Society
doi: 10.1213/01.ANE.0000135636.45389.E6

CARDIOVASCULAR ANESTHESIA

Protein Kinase C Inhibitors Produce Mitochondrial Flavoprotein Oxidation in Cardiac Myocytes

Shinji Kohro, MD PhD*, Quinn H. Hogan, MD*,||, David C. Warltier, MD PhD*,{ddagger},§,||, and Zeljko J. Bosnjak, PhD*,{dagger}

Departments of *Anesthesiology, {dagger}Physiology, {ddagger}Pharmacology, and §Medicine (Division of Cardiovascular Diseases), Medical College of Wisconsin, Milwaukee; and ||Clement J. Zablocki Veterans Affairs Medical Center, Milwaukee, Wisconsin

Address correspondence and reprint requests to Quinn H. Hogan, MD, Anesthesiology Research, Medical College of Wisconsin, 8701 Watertown Plank Rd., Milwaukee, WI 53226. Address e-mail to qhogan{at}mcw.edu


   Abstract
Top
 Abstract
Introduction
 Methods
 Results
 Discussion
 References
 
Inhibition of protein kinase C (PKC) antagonizes ischemic preconditioning of myocardium. Opening of mitochondrial adenosine triphosphate (ATP)-dependent potassium (mitoKATP) channels and subsequent oxidation of mitochondria are known to contribute to ischemic preconditioning. We therefore tested the effects of PKC inhibitors on flavoprotein oxidation, measured by flavoprotein fluorescence, as an index of mitoKATP activity in ventricular myocytes from guinea pigs. The PKC inhibitors chelerythrine (1 and 5 µM) and bisindolylmaleimide (100 and 400 nM) strongly increased flavoprotein oxidation in a dose-dependent manner. Specific inhibition of PKC-{delta} by rottlerin produced persistent flavoprotein oxidation. Inhibition of the production of inositol (1,4,5)-triphosphate by neomycin (0.5 mM) abolished chelerythrine- but not rottlerin-induced flavoprotein oxidation. Inhibition of PKC promotes flavoprotein oxidation via production of inositol (1,4,5)-triphosphate, possibly through the PKC-{delta} isoform. We speculate that although a certain degree of mitochondrial flavoprotein oxidation causes cardioprotective effects, excessive and/or persistent oxidation abolishes any beneficial actions. Instead of a simple mediator, PKC may act as a regulator of the mitoKATP channel to prevent excessive mitochondrial oxidation.

IMPLICATIONS: Inhibition of protein kinase C (PKC) blocks ischemic and anesthetic preconditioning of the myocardium. We observed that PKC inhibition produces intense oxidation of mitochondria by a pathway involving inositol triphosphate. This may indicate that PKC modulates adenosine triphosphate-sensitive K channels to prevent injurious mitochondrial oxidation.


   Introduction
Top
 Abstract
 Introduction
Methods
 Results
 Discussion
 References
 
Ischemic preconditioning (IPC) is a process by which a brief period of ischemia protects cardiomyocytes from infarction during a subsequent sustained ischemic insult (1). The precise mechanism of IPC remains unclear despite intensive investigation. Many reports indicate that activation of protein kinase C (PKC) by phorbol 12-myristate 13-acetate or 1,2-dioctanoyl-sn-glycerol (DAG) produces or potentiates the effects of ischemic or pharmacological preconditioning (2–6). PKC inhibitors, such as chelerythrine, reduce or abolish preconditioning (7–10), suggesting that PKC is an important mediator of IPC. Other studies have failed to support this hypothesis (11–15), and some reports demonstrate that moderate doses of PKC inhibitors actually produce preconditioning (15–18). Thus, PKC may not be a simple activator of preconditioning, but instead may act in concert with other elements of signal transduction in a complex manner.

Other intracellular signaling systems have been implicated in IPC. A role of phospholipase C (PLC), which ultimately activates PKC and is responsible for generating DAG and inositol (1,4,5)-triphosphate [Ins(1,4,5)P3] via hydrolysis of phosphatidylinositol 4,5-bisphosphate (PIP2), is supported by the finding of an increase in the myocardial concentration of Ins(1,4,5)P3 content in response to IPC (19). During IPC, the intracellular concentration of free Ca2+ ([Ca2+]i) was also demonstrated to be increased two- to fourfold, possibly in response to increased Ins(1,4,5)P3 levels (20). Two studies indi-cate that mitochondrial adenosine triphosphate (ATP)-dependent potassium (mitoKATP) channels are one of the final effectors in IPC (6,21). Opening of these channels may promote mitochondrial oxidation.

The present investigation was designed to clarify the role of PKC in IPC by examining the effects of PKC on mitochondrial redox potential as measured by flavoprotein fluorescence (6,21) in mitochondria of dissociated guinea pig cardiac myocytes. We used the nonselective PKC inhibitors chelerythrine and bisindolylmaleimide (BIS), as well as rottlerin, which selectively blocks the {delta} isoform of PKC. Additionally, to investigate the mechanism by which PKC inhibitors alter mitochondrial redox state, we determined the effect of blocking Ins(1,4,5)P3 formation on the actions of chelerythrine or rottlerin.


   Methods
Top
 Abstract
 Introduction
 Methods
Results
 Discussion
 References
 
This study was conducted according to National Institutes of Health standards (NIH Publication 95-23, revised 1996) and was approved by the Medical College of Wisconsin Animal Care and Use Committee.

Cell Isolation
Single cardiac myocytes were isolated from ventricles of anesthetized guinea pigs of either sex weighing 150–200 g. Guinea pigs were injected intraperitoneally with sodium pentobarbital (70 mg/kg) and heparin (1000 U). The thoracic cavities were opened, and the hearts were quickly excised. Each heart was mounted on a Langendorff apparatus and perfused via the aorta with an oxygenated buffer solution containing Joklik minimum essential medium. Each was then perfused for 14 min with an enzyme solution containing 0.4 mg/mL collagenase (Type II) and 0.17 mg/mL protease (Type XIV) in Joklik medium. The digested ventricular tissue was coarsely divided into small fragments and shaken in a water bath for further dispersion. The cells were filtered, centrifuged, and washed. Only rod-shaped cells with clear borders and striations were selected for experiments. Cardiomyocytes were used for experimentation within 8 h of isolation.

Flavoprotein Fluorescence Measurements
Mitochondrial redox state was assessed by measuring the autofluorescence of flavin adenine dinucleotide-linked enzymes in the mitochondria (6,21). Cells were superfused with modified Tyrode’s solution containing (in millimolar) 140 NaCl, 5 KCl, 1 MgCl2, 10 HEPES, 2 CaCl2 (pH 7.4 with NaOH). As in previous studies (6,22,23), experiments were performed at room temperature (21°C) to assure stability of the cells. Endogenous flavoprotein fluorescence was excited every 30 s with light from a Xenon laser (Noran, Middleton, WI), bandpass filtered to 488 ± 20 nm. Emitted fluorescence was recorded using a 515-nm long pass filter. Relative fluorescence was averaged during the excitation. Fluorescence images were obtained with 40x oil immersion objective lenses on a Nikon inverted microscope. The values of fluorescence intensity were expressed as arbitrary units (au) (range, 0–256).

Fluorescence Intensity Calibration
Resting fluorescence intensity of 15–25 au was achieved before each experiment by adjusting laser power (nominal range, 30%–60%). Calibration of flavoprotein fluorescence (6,21) with dinitrophenol and cyanide was not performed, because preliminary studies showed strong and irreversible effects of PKC inhibitors on flavoprotein oxidation. Background fluorescence from cell-free solutions of chelerythrine, rottlerin, BIS, and neomycin were subtracted from flavoprotein fluorescence determinations when these agents were used.

Effects of PKC Inhibitors on Flavoprotein Fluorescence
The half-maximal inhibitory concentration for PKC inhibition with chelerythrine has been reported to be 0.66 µM (24). We used 1 µM to achieve a mid-range effect and 5 µM to determine responses to maximal inhibition. The half-maximal inhibitory concentration of BIS is 10 nM (25). We selected 100 and 400 nM following the report of Toller et al. (17) that these concentrations of BIS demonstrated a biphasic effect. The PKC inhibitor rottlerin was used in a concentration of 10 µM that selectively inhibits the PKC-{delta} isoform (26). Baseline values of fluorescence intensity were measured after 10 min of equilibration in glucose-free modified Tyrode’s solution, 5 min after application of the PKC inhibitors, and finally 15 min after washout with glucose-free modified Tyrode’s solution. Each preparation was exposed to only a single concentration of each agent. To test the participation of mitoKATP in the actions of PKC inhibition, in a separate group of cells, we measured flavoprotein fluorescence during chelerythrine administration with and without coadministration of the selective mitoKATP blocker 5-hydroxydecanoate (5-HD).

Effects of Neomycin on Chelerythrine- or Rottlerin-Induced Flavoprotein Fluorescence Changes
Neomycin has been described to have biphasic effects depending on concentration (19). Large concentrations (30 mM) of neomycin inhibit the activation of PLC. Small concentrations (0.3 mM) fail to inhibit the activation of PLC but do inhibit the subsequent production of Ins(1,4,5)P3 secondary to the hydrolysis of PIP2 by PLC. In the present study, 0.5 mM neomycin was used to block Ins(1,4,5)P3 release without inhibiting either production of DAG or PKC (19). After a 10 min equilibration period, cardiomyocytes were incubated with neomycin for 10 min before coadministration of chelerythrine (1 µM) or rottlerin (10 µM) with neomycin (0.5 mM). These drugs were then washed out using fresh Tyrode’s buffer for 15 min. Responses to chelerythrine (1 µM) or rottlerin (10 µM) were compared with or without neomycin using myocytes isolated from the same animals.

Data are presented as mean ± SD and the number of cells is shown as n. Analysis of variance combined with Fisher’s post hoc test or unpaired t-test was used to assess differences in fluorescence data.


   Results
Top
 Abstract
 Introduction
 Methods
 Results
Discussion
 References
 
Effects of PKC Inhibitors on Flavoprotein Fluorescence
No differences in baseline flavoprotein fluorescence were present in any experimental group. A typical trace of chelerythrine-induced change in flavoprotein fluorescence is shown in Figure 1A. These results were quite unusual because chelerythrine caused an initial increase in flavoprotein oxidation to be followed by an even larger increase during the washout. This persistent increase in fluorescence was caused by both small and large concentrations of chelerythrine (n = 7 in each group; Fig. 1B). Flavoprotein fluorescence increased from 15.1 ± 4.1 at baseline to 28.4 ± 3.6 au at the end of administration of the small concentration of chelerythrine. Large concentrations of chelerythrine increased fluorescence from 16.5 ± 2.9 to 43.9 ± 16.9 au (P < 0.01 baseline versus small or large concentrations of chelerythrine). Fluorescence continued to increase to 47.0 ± 15.0 (small concentration) and 99.2 ± 7.8 au (large concentration) 15 min after the washout of chelerythrine (P < 0.01 versus end of administration of small and large concentrations of chelerythrine).



View larger version (18K):
[in this window]
[in a new window]
  		Figure 1. Flavoprotein oxidation by protein kinase C inhibitor chelerythrine. A, Typical trace of flavoprotein fluorescence change by 5 µM chelerythrine. Fluorescence continues to increase even after discontinuation of chelerythrine administration. B, Both concentrations of chelerythrine demonstrated persistent increases of flavoprotein oxidation. n = 7 in each group. Arrows indicate timing of data for B. *P < 0.01 and #P < 0.05 versus baseline. {dagger}P < 0.01 versus chelerythrine.

 
An example of alteration of flavoprotein fluorescence oxidation by BIS is depicted in Figure 2A. BIS (100 nM [n = 5] or 400 nM [n = 7]) produced a reversible increase in fluorescence (Fig. 2B). Flavoprotein fluorescence increased from 16.4 ± 2.6 at baseline to 32.5 ± 11.0 au at the end of administration of small concentrations of BIS. Large concentrations of BIS caused further increases in fluorescence from 24.8 ± 2.2 to 101.6 ± 12.7 au (P < 0.01). After washout, flavoprotein fluorescence returned to near baseline levels present before administration of BIS.



View larger version (17K):
[in this window]
[in a new window]
  		Figure 2. Typical trace (A) and summarized data (B) for flavoprotein oxidation by protein kinase C inhibitor bisindolylmaleimide (BIS). BIS 100 nM demonstrated reversible increase of flavoprotein oxidation, although 400 nM BIS demonstrated incomplete reversal with washout. n = 7 in 400 nM, n = 6 in 100 nM. *P < 0.01 versus baseline, {dagger}P < 0.01 versus BIS 400 nM.

 
A typical trace of rottlerin-induced flavoprotein oxidation is shown in Figure 3A. Rottlerin (n = 6) caused an increase in flavoprotein fluorescence (Fig. 3B) from 25.2 ± 4.9 at baseline to 46.8 ± 5.6 au at the end of drug administration (P < 0.01). During washout, fluorescence continued to increase to 57.4 ± 7.2 au (P < 0.01 versus end of rottlerin administration).



View larger version (15K):
[in this window]
[in a new window]
  		Figure 3. Typical trace (A) and summarized data (B) for flavoprotein oxidation by protein kinase C-{delta}-specific inhibitor rottlerin (10 µM). Rottlerin increased flavoprotein oxidation, which persisted during washout. n = 6. *P < 0.01 versus baseline, {dagger}P < 0.01 versus rottlerin.

 
In the presence of 5-HD (n = 7), chelerythrine increased flavoprotein fluorescence from 9.2 ± 1.8 to 51.0 ± 15.5 au, compared with an increase from 12.7 ± 3.9 to 77.3 ± 15.5 au with chelerythrine alone (n = 9, P < 0.01; Fig. 4). This confirms that a component of the chelerythrine effect is dependent on mitoKATP opening.



View larger version (15K):
[in this window]
[in a new window]
  		Figure 4. Inhibition of chelerythrine effect on flavoprotein oxidation by the mitochondrial adenosine triphosphate-dependent potassium (mitoKATP) blocker 5-hydroxydecanoate (5-HD). This demonstrates that a component of the flavoprotein oxidation is caused by opening of mitoKATP channels. n = 7 with 5-HD, n = 9 without 5-HD. *P < 0.01 with 5-HD versus without 5-HD.

 
Effects of Neomycin on Chelerythrine- or Rottlerin-Induced Flavoprotein Oxidation
Chelerythrine alone induced an increase in flavoprotein fluorescence (from 24.6 ± 3.1 to 31.5 ± 2.5 au) that was eliminated by neomycin (22.0 ± 5.7 au, P < 0.01 versus chelerythrine alone; Fig. 5). The increase in fluorescence after washout of chelerythrine (51.3 ± 6.8 au) was also eliminated by neomycin (23.1 ± 6.1 au, P < 0.01 versus chelerythrine alone). Rottlerin caused an increase in flavoprotein fluorescence (from 23.3 ± 3.5 to 38.6 ± 11.3 au) that was not affected by neomycin (34.0 ± 4.6 au; Fig. 6). Neomycin also did not alter the increase in fluorescence that followed washout of rottlerin (62.3 ± 8.4 au for rottlerin alone versus 63.5 ± 14.7 au for rottlerin plus neomycin; Fig. 6).



View larger version (17K):
[in this window]
[in a new window]
  		Figure 5. Inhibitory effect of specific inositol (1,4,5)-triphosphate inhibitor neomycin (0.5 mM) on chelerythrine-induced flavoprotein oxidation. Neomycin completely abolished chelerythrine-induced flavoprotein oxidation. n = 7 in each group. *P < 0.01 chelerythrine versus chelerythrine plus neomycin.

 


View larger version (17K):
[in this window]
[in a new window]
  		Figure 6. Effect of specific inositol (1,4,5)-triphosphate inhibitor neomycin (0.5 mM) on rottlerin-induced flavoprotein oxidation. Neomycin did not abolish rottlerin-induced flavoprotein oxidation. n = 6 in each group.

 

   Discussion
Top
 Abstract
 Introduction
 Methods
 Results
 Discussion
References
 
Substantial previous work has characterized the KATP channel to have a central and critical role in IPC. Early hypotheses proposed that sarcolemmal KATP channel opening was a primary mechanism of preconditioning, and that opening of these channels causes shortening of action potential duration and limitation of the influx of Ca2+ through L-type channels (27). Several studies show that sarcolemmal KATP opening may not be necessary for IPC (28,29). Examination of the relationship between mitoKATP and cardioprotection using specific mitoKATP channel openers and antagonists established the importance of the mitochondrial channel in IPC. Diazoxide, a specific mitoKATP channel opener that induces pharmacological preconditioning, has been shown to produce a reversible oxidation of flavoproteins (21,30). However, an increase in autofluorescence in response to diazoxide was not detected in other studies, perhaps because of differences in substrate availability (31). Other reports have demonstrated that PKC inhibitors can block ischemic or pharmacological preconditioning, and have concluded that PKC is a mediator of signal transduction for preconditioning of myocardium (7–10).

We predicted that PKC inhibitors would reduce mitoKATP activation, as measured by flavoprotein fluorescence, based on prior findings (6–10,21,32) and on our earlier observation of increased mitochondrial flavoprotein fluorescence with PKC activation (22). In contrast, the present results indicate that PKC inhibitors produce mitochondrial flavoprotein oxidation. Specifically, chelerythrine and rottlerin cause a persistent increase in flavoprotein oxidation, whereas BIS produces a reversible increase. These findings may not be applicable in all species, because chelerythrine has been shown to have no effect on mitochondrial flavoprotein fluorescence in rat cardiac myocytes (33). Our data further support a pathway involving mitoKATP opening, because a component of the effect is blocked by 5-HD. We note, however, that 5-HD has additional actions at sites other than the mitoKATP channel (23).

The mechanism by which inhibition of PKC produces flavoprotein fluorescence is unclear but may be related to the PKC inhibitors having partial agonist properties. Alternatively, PKC may have some feedback effect upstream in the signal transduction process. To examine this, we measured flavoprotein fluorescence during coadministration of chelerythrine and the Ins(1,4,5)P3 inhibitor neomycin. A small concentration of neomycin (0.5 mM) was shown to affect only Ins(1,4,5)P3 production but not PLC (19). A decrease in the inositol 1,4,5-trisphosphate production would prevent the inositol 1,4,5-trisphosphate-induced calcium release from the sarcoplasmic reticulum. The stimulation of the membrane effector PLC hydrolyzes PIP2, resulting in production of two second messengers: Ins(1,4,5)P3, which facilitates Ca2+ release from internal stores, and DAG, which activates phosphatidylserine and PKC. PKC isozymes in turn catalyze protein phosphorylation, an essential signaling step for cellular activation and subsequent biological responses. Bauer et al. (19) demonstrated that myocardial Ins(1,4,5)P3 content increased in response to IPC stimuli, consistent with the concept that Ins(1,4,5)P3 may be a potential mediator of IPC in isolated rabbit hearts. In the present study, the specific Ins(1,4,5)P3 inhibitor neomycin (0.5 mM) completely abolished the flavoprotein oxidation induced by chelerythrine. If chelerythrine has partial PKC activating effects, small dose neomycin would not be expected to eliminate the increase in fluorescence produced by chelerythrine. Thus, the chelerythrine-induced increase in flavoprotein fluorescence does not depend on direct activation of PKC. The data also indicate that the action of rottlerin is not inhibited by neomycin. We further speculate that there are certain PKC isoforms that induce mitochondrial oxidation.

There are several reports that support our results and demonstrate that cardioprotective effects can be caused by PKC inhibitors (15–18). Lasley et al. (16) reported that pretreatment with BIS (1 µM) or chelerythrine (2 µM) markedly reduced myocardial infarct size secondary to 45-minute ischemia and 60-minute reperfusion. Contrasting results were obtained when a 5-minute IPC preceded the 45-minute ischemia and 60-minute reperfusion. So chelerythrine (2 µM) abolished cardioprotection by IPC under these conditions. Finally, the difference in duration of administration of PKC inhibitors may lead to different levels of flavoprotein oxidation and cause contrasting effects on infarct size.

Toller et al. (17) have shown that a small intracoronary dose of BIS (2 µg/min equivalent to 100 nM) directly promoted recovery of contractile function after ischemia and reperfusion, whereas 8 µg/min (equivalent to 400 nM) did not. Furthermore, the larger dose of BIS abolished the beneficial effect of pharmacological preconditioning by isoflurane (17). Similarly, Kawamura et al. (34) showed that BIS (100 nM) did not affect preconditioning, but chelerythrine (1 µM) abolished the effect. In the present study, 100 nM BIS moderately increased flavoprotein oxidation, but 400 nM BIS increased flavoprotein oxidation to a much larger extent and, similar to chelerythrine and rottlerin, produced further increases in flavoprotein fluorescence after washout. Taken together, these findings indicate that long-lasting or excessive mitochondrial flavoprotein oxidation inhibits preconditioning, whereas transient and/or moderate oxidation is beneficial.

Both chelerythrine and BIS are reported to be effective blockers (24) that are more selective for PKC than protein kinase A, calcium/calmodulin-dependent protein kinase, or tyrosine protein kinase, unlike the less selective actions of other widely used inhibitors, such as staurosporine and polymyxin B (8). Chelerythrine interacts with the catalytic domain of PKC (24), but BIS interacts with the PKC ATP-binding site (25). This difference between chelerythrine and BIS may account for the difference in reversibility of their effects on flavoprotein oxidation and subsequent cardioprotective actions.

The present investigation also demonstrates that the PKC-{delta}-specific inhibitor, rottlerin, produces persistent flavoprotein oxidation. This finding implies that inhibition of the {delta} isoform is at least partially responsible for the long-lasting flavoprotein oxidation caused by other PKC inhibitors. Therefore, PKC-{delta} may have a role in maintaining the level of mitochondrial oxidation at an optimal level, thus contributing indirectly to protection of ischemic myocardium by preconditioning.

PKC inhibitors promote flavoprotein oxidation by Ins(1,4,5)P3 production, possibly via the PKC-{delta} isozyme. We speculate that appropriate mitochondrial flavoprotein oxidation may induce cardioprotective effects, but excessive and/or irreversible oxidation abolishes any beneficial action. PKC may thus act as a regulator of mitochondrial oxidation preventing excess oxidation, and ultimately allowing cardiac preconditioning in vivo.


   Acknowledgments
 
Supported in part by National Institutes of Health Grants HL34708 and GM66730, and Department of Anesthesiology, Sapporo Medical University, Sapporo, Japan (Prof. Akiyoshi Namiki).

The authors thank Anita Tredeau for her assistance in preparing the manuscript.


   References
Top
 Abstract
 Introduction
 Methods
 Results
 Discussion
 References
 

  1. Murry CE, Jennings RB, Reimer KA. Preconditioning with ischemia: a delay of lethal cell injury in ischemic myocardium. Circulation 1986; 74: 1124–36.[Abstract/Free Full Text]
  2. Chen W, Glasgow W, Murphy E, Steenbergen C. Lipoxygenase metabolism of arachidonic acid in ischemic preconditioning and PKC-induced protection in heart. Am J Physiol Heart Circ Physiol 1999; 276: H2094–101.[Abstract/Free Full Text]
  3. Liang BT. Protein kinase C-dependent activation of KATP channel enhances adenosine-induced cardioprotection. Biochem J 1998; 336: 337–43.
  4. Liu Y, Gao WD, O’Rourke B, Marban E. Synergistic modulation of ATP-sensitive K+ currents by protein kinase C and adenosine: implications for ischemic preconditioning. Circ Res 1996; 78: 443–54.[Abstract/Free Full Text]
  5. Qiu Y, Ping P, Tang XL, et al. Direct evidence that protein kinase C plays an essential role in the development of late preconditioning against myocardial stunning in conscious rabbits and that epsilon is the isoform involved. J Clin Invest 1998; 101: 2182–98.[ISI][Medline]
  6. Sato T, O’Rourke B, Marban E. Modulation of mitochondrial ATP-dependent K+ channels by protein kinase C. Circ Res 1998; 83: 110–4.[Abstract/Free Full Text]
  7. Fryer RM, Schultz JE, Hsu AK, Gross GJ. Importance of PKC and tyrosine kinase in single or multiple cycles of preconditioning in rat hearts. Am J Physiol Heart Circ Physiol 1999; 276: H1229–35.[Abstract/Free Full Text]
  8. Liu Y, Cohen MV, Downey JM. Chelerythrine, a highly selective protein kinase C inhibitor, blocks the anti-infarct effect of ischemic preconditioning in rabbit hearts. Cardiovasc Drugs Ther 1994; 8: 881–2.[ISI][Medline]
  9. Ping P, Zhang J, Cao X, et al. PKC-dependent activation of p44/p42 MAPKs during myocardial ischemia-reperfusion in conscious rabbits. Am J Physiol Heart Circ Physiol 1999; 276: H1468–81.[Abstract/Free Full Text]
  10. Wang Y, Hirai K, Ashraf M. Activation of mitochondrial ATP-sensitive K(+) channel for cardiac protection against ischemic injury is dependent on protein kinase C activity. Circ Res 1999; 85: 731–41.[Abstract/Free Full Text]
  11. Moolman JA, Genade S, Tromp E, Lochner A. No evidence for mediation of ischemic preconditioning by alpha 1-adrenergic signal transduction pathway or protein kinase C in the isolated rat heart. Cardiovasc Drugs Ther 1996; 10: 125–36.[ISI][Medline]
  12. Przyklenk K, Sussman MA, Simkhovich BZ, Kloner RA. Does ischemic preconditioning trigger translocation of protein kinase C in the canine model? Circulation 1995; 92: 1546–57.[Abstract/Free Full Text]
  13. Simkhovich BZ, Przyklenk K, Hale SL, et al. Direct evidence that ischemic preconditioning does not cause protein kinase C translocation in rabbit heart. Cardiovasc Res 1996; 32: 1064–70.[Abstract/Free Full Text]
  14. Vahlhaus C, Schulz R, Post H, et al. No prevention of ischemic preconditioning by the protein kinase C inhibitor staurosporine in swine. Circ Res 1996; 79: 407–14.[Abstract/Free Full Text]
  15. Vogt AM, Htun P, Arras M, et al. Intramyocardial infusion of tool drugs for the study of molecular mechanisms in ischemic preconditioning. Basic Res Cardiol 1996; 91: 389–400.[ISI][Medline]
  16. Lasley RD, Noble MA, Mentzer RM Jr. Effects of protein kinase C inhibitors in in situ and isolated ischemic rabbit myocardium. J Mol Cell Cardiol 1997; 29: 3345–56.[ISI][Medline]
  17. Toller WG, Montgomery MW, Pagel PS, et al. Isoflurane-enhanced recovery of canine stunned myocardium: role for protein kinase C? Anesthesiology 1999; 91: 713–22.[ISI][Medline]
  18. Tosaki A, Maulik N, Englelman DT, et al. The role of protein kinase in C ischemic/reperfused preconditioned isolated rat hearts. J Cardiovasc Pharmacol 1996; 28: 723–31.[ISI][Medline]
  19. Bauer B, Simkhovich BZ, Kloner RA, Przyklenk K. Preconditioning-induced cardioprotection and release of the second messenger inositol (1,4,5)-trisphosphate are both abolished by neomycin in rabbit heart. Basic Res Cardiol 1999; 94: 31–40.[ISI][Medline]
  20. Smith GB, Stefenelli T, Wu ST, et al. Rapid adaptation of myocardial calcium homeostasis to short episodes of ischemia in isolated rat hearts. Am Heart J 1996; 131: 1106–12.[ISI][Medline]
  21. Liu Y, Sato T, O’Rourke B, Marban E. Mitochondrial ATP-dependent potassium channels: novel effectors of cardioprotection? Circulation 1998; 97: 2463–9.[Abstract/Free Full Text]
  22. Nakae Y, Kohro S, Hogan QH, Bosnjak ZJ. Intracellular mechanism of mitochondrial adenosine triphosphate-sensitive potassium channel activation with isoflurane. Anesth Analg 2003; 97: 1025–32.[Abstract/Free Full Text]
  23. Hanley PJ, Mickel M, Loffler M, et al. K(ATP) channel-independent targets of diazoxide and 5-hydroxydecanoate in the heart. J Physiol 2002; 542: 735–41.[Abstract/Free Full Text]
  24. Herbert JM, Augereau JM, Gleye J, Maffrand JP. Chelerythrine is a potent and specific inhibitor of protein kinase C. Biochem Biophys Res Commun 1990; 172: 993–9.[ISI][Medline]
  25. Toullec D, Pianetti P, Coste H, et al. The bisindolylmaleimide GF 109203X is a potent and selective inhibitor of protein kinase C. J Biol Chem 1991; 266: 15771–81.[Abstract/Free Full Text]
  26. Gschwendt M, Muller HJ, Kielbassa K, et al. Rottlerin, a novel protein kinase inhibitor. Biochem Biophys Res Commun 1994; 199: 93–8.[ISI][Medline]
  27. Cole WC, McPherson CD, Sontag D. ATP-regulated K+ channels protect the myocardium against ischemia/reperfusion damage. Circ Res 1991; 69: 571–81.[Abstract/Free Full Text]
  28. Grover GJ, D’Alonzo AJ, Dzwonczyk S, et al. Preconditioning is not abolished by the delayed rectifier K+ blocker dofetilide. Am J Physiol Heart Circ Physiol 1996; 271: H1207–14.[Abstract/Free Full Text]
  29. Yao Z, Gross GJ. Effects of the KATP channel opener bimakalim on coronary blood flow, monophasic action potential duration, and infarct size in dogs. Circulation 1994; 89: 1769–75.[Abstract/Free Full Text]
  30. Garlid KD, Paucek P, Yarov-Yarovoy V, et al. Cardioprotective effect of diazoxide and its interaction with mitochondrial ATP-sensitive K+ channels: possible mechanism of cardioprotection. Circ Res 1997; 81: 1072–82.[Abstract/Free Full Text]
  31. Lawrence CL, Billups B, Rodrigo GC, Standen NB. The KATP channel opener diazoxide protects cardiac myocytes during metabolic inhibition without causing mitochondrial depolarization or flavoprotein oxidation. Br J Pharmacol 2001; 134: 535–42.[ISI][Medline]
  32. Baines CP, Liu GS, Birincioglu M, et al. Ischemic preconditioning depends on interaction between mitochondrial KATP channels and actin cytoskeleton. Am J Physiol Heart Circ Physiol 1999; 276: H1361–8.[Abstract/Free Full Text]
  33. Zaugg M, Lucchinetti E, Spahn DR, et al. Volatile anesthetics mimic cardiac preconditioning by priming the activation of mitochondrial K(ATP) channels via multiple signaling pathways. Anesthesiology 2002; 97: 4–14.[ISI][Medline]
  34. Kawamura S, Yoshida K, Miura T, et al. Ischemic preconditioning translocates PKC-delta and -epsilon, which mediate functional protection in isolated rat heart. Am J Physiol Heart Circ Physiol 1998; 275: H2266–71.[Abstract/Free Full Text]
Accepted for publication May 25, 2004.




This article has been cited by other articles:


Home page
 Am. J. Physiol. Heart Circ. Physiol.Home page
K. Przyklenk, M. Maynard, and P. Whittaker
Reduction of infarct size with D-myo-inositol trisphosphate: role of PI3-kinase and mitochondrial KATP channels
Am J Physiol Heart Circ Physiol, February 1, 2006; 290(2): H830 - H836.
[Abstract] [Full Text] [PDF]

This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a colleague
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
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 ISI Web of Science (2)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Kohro, S.
Right arrow Articles by Bosnjak, Z. J.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Kohro, S.
Right arrow Articles by Bosnjak, Z. J.
Related Collections
Right arrow Heart
Right arrow Pharmacology

Lippincott, Williams & Wilkins Anesthesia & Analgesia® is published for the International Anesthesia Research Society® by Lippincott Williams & Wilkins with the assistance of Stanford University Libraries' HighWire Press®. Copyright 2006 by the International Anesthesia Research Society. Online ISSN: 1526-7598   Print ISSN: 0003-2999 HighWire Press