Limits...
Remote ischemic preconditioning of cardiomyocytes inhibits the mitochondrial permeability transition pore independently of reduced calcium-loading or sarcKATP channel activation.

Turrell HE, Thaitirarot C, Crumbie H, Rodrigo G - Physiol Rep (2014)

Bottom Line: However, only conventional-IPC reduced the Ca(2+)-loading during metabolic inhibition and this was independent of any change in sarcKATP channel activity but was associated with a reduction in Na(+)-loading, reflecting a decrease in Na/H exchanger activity.These data show that remote-IPC inhibits MPT pore opening to a similar degree as conventional IPC, however, the contribution of MPT pore inhibition to protection against reperfusion injury is independent of Ca(2+)-loading in remote IPC.We suggest that inhibition of the MPT pore and not Ca(2+)-loading is the common link in cardioprotection between conventional and remote IPC.

View Article: PubMed Central - PubMed

Affiliation: Department of Cardiovascular Sciences, University of Leicester, Glenfield General Hospital, Leicester, UK.

No MeSH data available.


Related in: MedlinePlus

Intracellular sodium concentrations (SBFI ratio) in conventional and remotely preconditioned myocytes subject to MI and reenergization. (A) (i) Recordings of SBFI ratio as an indicator of [Na+]i in a control naïve‐myocyte (black trace), conventional IPC‐myocyte (dark gray), and remote IPC myocyte (light gray) during perfusion with MI‐Tyrode. (ii) Mean data ± SEM of the SBFI ratio recorded in normal Tyrode (NT) and at the end of 8 min perfusion with MI‐Tyrode (as indicated on 4Ai). (B) (i) Recordings of SBFI ratio in a control naïve‐myocyte (black trace) and a naïve‐myocyte in the presence of amiloride (dark gray) during perfusion with MI‐Tyrode. (ii) Mean data ± SEM of the SBFI ratio recorded in normal Tyrode (NT) and at the end of 8 min perfusion with MI‐Tyrode. *P < 0.05, ***P < 0.001, one‐way ANOVA followed by Tukey's post hoc test for significance. Control naïve‐myocytes = 5 hearts; 50 cells, conventional IPC‐myocytes = 5; 45, remote IPC‐myocytes = 5; 38, and Control naïve‐myocytes + amiloride = 3; 18.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4255825&req=5

fig05: Intracellular sodium concentrations (SBFI ratio) in conventional and remotely preconditioned myocytes subject to MI and reenergization. (A) (i) Recordings of SBFI ratio as an indicator of [Na+]i in a control naïve‐myocyte (black trace), conventional IPC‐myocyte (dark gray), and remote IPC myocyte (light gray) during perfusion with MI‐Tyrode. (ii) Mean data ± SEM of the SBFI ratio recorded in normal Tyrode (NT) and at the end of 8 min perfusion with MI‐Tyrode (as indicated on 4Ai). (B) (i) Recordings of SBFI ratio in a control naïve‐myocyte (black trace) and a naïve‐myocyte in the presence of amiloride (dark gray) during perfusion with MI‐Tyrode. (ii) Mean data ± SEM of the SBFI ratio recorded in normal Tyrode (NT) and at the end of 8 min perfusion with MI‐Tyrode. *P < 0.05, ***P < 0.001, one‐way ANOVA followed by Tukey's post hoc test for significance. Control naïve‐myocytes = 5 hearts; 50 cells, conventional IPC‐myocytes = 5; 45, remote IPC‐myocytes = 5; 38, and Control naïve‐myocytes + amiloride = 3; 18.

Mentions: Figure 5Ai shows records of SBFI fluorescence ratio from a control naive, conventional IPC, and rIPC‐myocyte. Superfusion with MI‐Tyrode resulted in a biphasic increase in the ratio of SBFI fluorescence in control myocytes, with an initial rapid increase (Phase1) followed by a slower steady increase with continued superfusion with MI‐Tyrode (Phase 2). Phase 1 characterized by this rapid increase in SBFI‐ratio was similar in all three myocyte types and is probably due to the increase in NADH fluorescence associated with inhibition of electron transport by cyanide (Donoso et al. 1992). However, phase 2 of the increase in SBFI‐ratio reflects the increase in [Na+]i as shown by the decrease in F380, which has been shown to decrease fluorescence in response to an increase in [Na+]i ((Donoso et al. 1992) and Fig. 1).


Remote ischemic preconditioning of cardiomyocytes inhibits the mitochondrial permeability transition pore independently of reduced calcium-loading or sarcKATP channel activation.

Turrell HE, Thaitirarot C, Crumbie H, Rodrigo G - Physiol Rep (2014)

Intracellular sodium concentrations (SBFI ratio) in conventional and remotely preconditioned myocytes subject to MI and reenergization. (A) (i) Recordings of SBFI ratio as an indicator of [Na+]i in a control naïve‐myocyte (black trace), conventional IPC‐myocyte (dark gray), and remote IPC myocyte (light gray) during perfusion with MI‐Tyrode. (ii) Mean data ± SEM of the SBFI ratio recorded in normal Tyrode (NT) and at the end of 8 min perfusion with MI‐Tyrode (as indicated on 4Ai). (B) (i) Recordings of SBFI ratio in a control naïve‐myocyte (black trace) and a naïve‐myocyte in the presence of amiloride (dark gray) during perfusion with MI‐Tyrode. (ii) Mean data ± SEM of the SBFI ratio recorded in normal Tyrode (NT) and at the end of 8 min perfusion with MI‐Tyrode. *P < 0.05, ***P < 0.001, one‐way ANOVA followed by Tukey's post hoc test for significance. Control naïve‐myocytes = 5 hearts; 50 cells, conventional IPC‐myocytes = 5; 45, remote IPC‐myocytes = 5; 38, and Control naïve‐myocytes + amiloride = 3; 18.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4255825&req=5

fig05: Intracellular sodium concentrations (SBFI ratio) in conventional and remotely preconditioned myocytes subject to MI and reenergization. (A) (i) Recordings of SBFI ratio as an indicator of [Na+]i in a control naïve‐myocyte (black trace), conventional IPC‐myocyte (dark gray), and remote IPC myocyte (light gray) during perfusion with MI‐Tyrode. (ii) Mean data ± SEM of the SBFI ratio recorded in normal Tyrode (NT) and at the end of 8 min perfusion with MI‐Tyrode (as indicated on 4Ai). (B) (i) Recordings of SBFI ratio in a control naïve‐myocyte (black trace) and a naïve‐myocyte in the presence of amiloride (dark gray) during perfusion with MI‐Tyrode. (ii) Mean data ± SEM of the SBFI ratio recorded in normal Tyrode (NT) and at the end of 8 min perfusion with MI‐Tyrode. *P < 0.05, ***P < 0.001, one‐way ANOVA followed by Tukey's post hoc test for significance. Control naïve‐myocytes = 5 hearts; 50 cells, conventional IPC‐myocytes = 5; 45, remote IPC‐myocytes = 5; 38, and Control naïve‐myocytes + amiloride = 3; 18.
Mentions: Figure 5Ai shows records of SBFI fluorescence ratio from a control naive, conventional IPC, and rIPC‐myocyte. Superfusion with MI‐Tyrode resulted in a biphasic increase in the ratio of SBFI fluorescence in control myocytes, with an initial rapid increase (Phase1) followed by a slower steady increase with continued superfusion with MI‐Tyrode (Phase 2). Phase 1 characterized by this rapid increase in SBFI‐ratio was similar in all three myocyte types and is probably due to the increase in NADH fluorescence associated with inhibition of electron transport by cyanide (Donoso et al. 1992). However, phase 2 of the increase in SBFI‐ratio reflects the increase in [Na+]i as shown by the decrease in F380, which has been shown to decrease fluorescence in response to an increase in [Na+]i ((Donoso et al. 1992) and Fig. 1).

Bottom Line: However, only conventional-IPC reduced the Ca(2+)-loading during metabolic inhibition and this was independent of any change in sarcKATP channel activity but was associated with a reduction in Na(+)-loading, reflecting a decrease in Na/H exchanger activity.These data show that remote-IPC inhibits MPT pore opening to a similar degree as conventional IPC, however, the contribution of MPT pore inhibition to protection against reperfusion injury is independent of Ca(2+)-loading in remote IPC.We suggest that inhibition of the MPT pore and not Ca(2+)-loading is the common link in cardioprotection between conventional and remote IPC.

View Article: PubMed Central - PubMed

Affiliation: Department of Cardiovascular Sciences, University of Leicester, Glenfield General Hospital, Leicester, UK.

No MeSH data available.


Related in: MedlinePlus