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Updated: Jul 15, 2026
Murine Isolated Heart Model of Myocardial Stunning Associated with Cardioplegic Arrest
Published on: August 6, 2015
Nitroglycerin induces late preconditioning against arrhythmias but not stunning in conscious sheep
Elena C Lascano1, Héctor F Del Valle, Jorge A Negroni
1Department of Physiology, Pharmacology and Biochemistry, Favaloro University, Buenos Aires, Argentina. lascano@favaloro.edu.ar
Objectives:
Nitroglycerin, a nitric oxide donor, induces late preconditioning against stunning by short ischemia-reperfusion periods. The study purpose was to assess similar nitroglycerin protection against stunning and arrhythmias produced by prolonged reversible ischemia.
Design:
Four groups of conscious sheep were studied, control: 12 minutes ischemia and 2 hour reperfusion; late preconditioning: six periods of 5 min ischemia-5 min reperfusion 24 h before 12 min ischemia and late preconditioning with 120 microg/kg and 600 microg/kg nitroglycerin administered instead of the ischemia-reperfusion periods.
Results:
Although late preconditioning protected against stunning (mean postischemic recovery of wall thickening fraction, control (n=10): 54.8+/-3.2, late preconditioning (n=9): 74.4+/-3.0, p<0.01), nitroglycerin 120 microg/kg (n=6) did not reproduce mechanical protection (50.1+/-3.8), even with a higher concentration of 600 microg/kg (59.1+/-3.7, n=4). However, nitroglycerin decreased arrhythmia severity index (control: 2.3+/-0.6, late preconditioning: 0.5+/-0.4, nitroglycerin 120 microg/kg: 1+/-0.4 and 600 microg/kg: 0.1+/-0.1 (p<0.05 vs. control).
Conclusions:
Nitroglycerin only has a limited late preconditioning protective effect in conscious animals submitted to a reversible prolonged ischemia since it protects against arrhythmias but not against stunning.
