BACKGROUND: The objective of this study was to test the hypothesis that chemical interaction through gap junctions may result in cell-to-cell progression of hypercontracture and that this phenomenon contributes to the final extent of reperfused infarcts. METHODS AND RESULTS: Cell-to-cell transmission of hypercontracture was studied in pairs of freshly isolated adult rat cardiomyocytes. Hypercontracture induced by microinjection of a solution containing 1 mmol/L Ca2+ and 2% lucifer yellow (LY) was transmitted to the adjacent cell (11 of 11 pairs), and the gap junction uncoupler heptanol (2 mmol/L) prevented transmission in 6 of 8 pairs (P=.003), with a perfect association between passage of the LY and transmission of hypercontracture. In the isolated, perfused rat heart submitted to 30 minutes of hypoxia, addition of heptanol to the perfusion media during the first 15 minutes of reoxygenation had a dose-related protective effect against the oxygen paradox, as demonstrated by a reduction of diastolic pressure and marked recovery of developed pressure (P<.001), as well as less lactate dehydrogenase release during reoxygenation (P<.001) and less contraction band necrosis (P<.001) than controls. In the in situ pig heart submitted to 48 minutes of coronary occlusion, the intracoronary infusion of heptanol during the first 15 minutes of reperfusion at a final concentration of 1 mmol/L limited myocardial shrinkage, reflecting hypercontracture (P<.05), reduced infarct size after 5 hours of reperfusion by 54% (P=.04), and modified infarct geometry with a characteristic fragmentation of the area of necrosis. Heptanol at 1 mmol/L had no significant effect on contractility of nonischemic myocardium. CONCLUSIONS: These results demonstrate that hypercontracture may be transmitted to adjacent myocytes through gap junctions and that heptanol may interfere with this transmission and reduce the final extent of myocardial necrosis during reoxygenation or reperfusion. These findings are consistent with the hypothesis tested and open a new approach to limitation of infarct size by pharmacological control of gap junction conductance.
BACKGROUND: The objective of this study was to test the hypothesis that chemical interaction through gap junctions may result in cell-to-cell progression of hypercontracture and that this phenomenon contributes to the final extent of reperfused infarcts. METHODS AND RESULTS: Cell-to-cell transmission of hypercontracture was studied in pairs of freshly isolated adult rat cardiomyocytes. Hypercontracture induced by microinjection of a solution containing 1 mmol/L Ca2+ and 2% lucifer yellow (LY) was transmitted to the adjacent cell (11 of 11 pairs), and the gap junction uncoupler heptanol (2 mmol/L) prevented transmission in 6 of 8 pairs (P=.003), with a perfect association between passage of the LY and transmission of hypercontracture. In the isolated, perfused rat heart submitted to 30 minutes of hypoxia, addition of heptanol to the perfusion media during the first 15 minutes of reoxygenation had a dose-related protective effect against the oxygen paradox, as demonstrated by a reduction of diastolic pressure and marked recovery of developed pressure (P<.001), as well as less lactate dehydrogenase release during reoxygenation (P<.001) and less contraction band necrosis (P<.001) than controls. In the in situ pig heart submitted to 48 minutes of coronary occlusion, the intracoronary infusion of heptanol during the first 15 minutes of reperfusion at a final concentration of 1 mmol/L limited myocardial shrinkage, reflecting hypercontracture (P<.05), reduced infarct size after 5 hours of reperfusion by 54% (P=.04), and modified infarct geometry with a characteristic fragmentation of the area of necrosis. Heptanol at 1 mmol/L had no significant effect on contractility of nonischemic myocardium. CONCLUSIONS: These results demonstrate that hypercontracture may be transmitted to adjacent myocytes through gap junctions and that heptanol may interfere with this transmission and reduce the final extent of myocardial necrosis during reoxygenation or reperfusion. These findings are consistent with the hypothesis tested and open a new approach to limitation of infarct size by pharmacological control of gap junction conductance.
Authors: Hans Erik Bøtker; Derek Hausenloy; Ioanna Andreadou; Salvatore Antonucci; Kerstin Boengler; Sean M Davidson; Soni Deshwal; Yvan Devaux; Fabio Di Lisa; Moises Di Sante; Panagiotis Efentakis; Saveria Femminò; David García-Dorado; Zoltán Giricz; Borja Ibanez; Efstathios Iliodromitis; Nina Kaludercic; Petra Kleinbongard; Markus Neuhäuser; Michel Ovize; Pasquale Pagliaro; Michael Rahbek-Schmidt; Marisol Ruiz-Meana; Klaus-Dieter Schlüter; Rainer Schulz; Andreas Skyschally; Catherine Wilder; Derek M Yellon; Peter Ferdinandy; Gerd Heusch Journal: Basic Res Cardiol Date: 2018-08-17 Impact factor: 17.165
Authors: Marina V Frantseva; Larisa Kokarovtseva; Christian G Naus; Peter L Carlen; Derrick MacFabe; Jose L Perez Velazquez Journal: J Neurosci Date: 2002-02-01 Impact factor: 6.167
Authors: Marie Billaud; Alexander W Lohman; Scott R Johnstone; Lauren A Biwer; Stephanie Mutchler; Brant E Isakson Journal: Pharmacol Rev Date: 2014-03-26 Impact factor: 25.468
Authors: Antonio Rodríguez-Sinovas; Jose Antonio Sánchez; Laura Valls-Lacalle; Marta Consegal; Ignacio Ferreira-González Journal: Int J Mol Sci Date: 2021-04-23 Impact factor: 5.923