Characterization of the Langendorff Perfused Isolated Mouse Heart Model of Global Ischemia-Reperfusion Injury: Impact of Ischemia and Reperfusion Length on Infarct Size and LDH Release.
The Langendorff perfused isolated mouse heart model is commonly used to assess the efficacy of cardioprotective therapies, although the duration of ischemia and reperfusion vary considerably between different laboratories. We aimed to provide a thorough characterization of the model with different durations of ischemia and reperfusion by means of 2 different end points-infarct size (IS) using triphenyltetrazolium staining and lactate dehydrogenase (LDH) release.



C57/BL6 mice hearts were retrograde perfused on a Langendorff apparatus and allocated into 9 groups in a 3 × 3 factorial design-3 ischemic durations (25, 35, and 45 minutes) matched by 3 reperfusion durations (60, 120, and 180 minutes). A protocol of ischemic preconditioning (IPC) was applied to investigate IS and LDH kinetics with different ischemic durations.



Infarct size progressively increased with the duration of both ischemia and reperfusion and was found to be independently associated with both determinants. In terms of LDH release kinetics, a peak was observed within the first 10 to 15 minutes of reperfusion and steadily declined thereafter, although a second smaller peak was observed in the 25-minute ischemia group. Only LDH peak release was associated with the ischemia length, with area under the curve (AUC) failing to follow ischemic duration. Interestingly, while IPC reduced IS in all ischemic durations investigated, a significant attenuation of LDH AUC was only observed in the 25-minute index ischemia group. Only a moderately positive correlation was observed between IS and LDH peak (R = .547, P = .006) and AUC (R = .664, P < .001).



Myocardial IS measured by triphenyltetrazolium staining depends on both the duration of ischemia and the length of the reperfusion period. The LDH assessment may not be the most reliable tool to assess IS and/or to examine cardioprotective effectiveness at various times of ischemia.
The Hatter Cardiovascular Institute, University College London, London, United Kingdom.
Xavier
X
Rossello
The Hatter Cardiovascular Institute, University College London, London, United Kingdom.
Andrew R
AR
Hall
The Hatter Cardiovascular Institute, University College London, London, United Kingdom.
Robert M
RM
Bell
The Hatter Cardiovascular Institute, University College London, London, United Kingdom NIHR UCLH Biomedical Research Centre, University College London Hospital & Medical School, London, United Kingdom d.yellon@ucl.ac.uk.
Derek M
DM
Yellon
D000818:Animals; D019540:Area Under Curve; D015415:Biomarkers / Q000378:metabolism; D004195:Disease Models, Animal; D000067268:Isolated Heart Preparation; D007770:L-Lactate Dehydrogenase / Q000378:metabolism*; D008297:Male; D008810:Mice, Inbred C57BL; D009203:Myocardial Infarction / Q000201:enzymology* / Q000473:pathology*; D015425:Myocardial Reperfusion / Q000009:adverse effects / Q000379:methods*; D015428:Myocardial Reperfusion Injury / Q000201:enzymology* / Q000473:pathology*; D009206:Myocardium / Q000201:enzymology* / Q000473:pathology*; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D013194:Staining and Labeling / Q000379:methods; D013997:Time Factors
D015415:Biomarkers; D007770:L-Lactate Dehydrogenase
ischemia preconditioning; ischemia–reperfusion; myocardial infarction