Differential contribution of necrosis and apoptosis in myocardial ischemia-reperfusion injury

• Published in: American journal of physiology. Heart and circulatory physiology Vol. 286; no. 5; pp. H1923 - H1935
• Main Authors: McCully, James D, Wakiyama, Hidetaka, Hsieh, Yng-Ju, Jones, Mara, Levitsky, Sidney
• Format: Journal Article
• Language: English
• Published: United States 01.05.2004
• Subjects: Animals; Apoptosis; Caspase Inhibitors; Caspases - chemistry; Cysteine Proteinase Inhibitors - pharmacology; Hemodynamics; In Situ Nick-End Labeling; Myocardial Contraction; Myocardial Infarction - pathology; Myocardial Ischemia - pathology; Myocardial Ischemia - physiopathology; Myocardial Reperfusion Injury - pathology; Myocardial Reperfusion Injury - physiopathology; Necrosis; Oligopeptides - pharmacology; Rabbits; Recovery of Function
• ISSN: 0363-6135; 1522-1539
• DOI: 10.1152/ajpheart.00935.2003

Division of Cardiothoracic Surgery, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02115 Submitted 1 October 2003 ; accepted in final form 5 January 2004 Necrosis and apoptosis differentially contribute to myocardial injury. Determination of the contribution of these processes in ischemia-reperfusion injury would allow for the preservation of myocardial tissue. Necrosis and apoptosis were investigated in Langendorff-perfused rabbit hearts ( n = 47) subjected to 0 (Control group), 5 (GI-5), 10 (GI-10), 15 (GI-15), 20 (GI-20), 25 (GI-25), and 30 min (GI-30) of global ischemia (GI) and 120 min of reperfusion. Myocardial injury was determined by triphenyltetrazolium chloride (TTC) staining, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL), bax, bcl2, poly(ADP)ribose polymerase (PARP) cleavage, caspase-3, -8, and -9 cleavage and activity, Fas ligand (FasL), and Fas-activated death domain (FADD). The contribution of apoptosis was determined separately ( n = 42) using irreversible caspase-3, -8, and -9 inhibitors. Left ventricular peak developed pressure (LVPDP) and systolic shortening (SS) were significantly decreased and infarct size and TUNEL-positive cells were significantly increased ( P < 0.05 vs. Control group) at GI-20, GI-25, and GI-30. Proapoptotic bax, PARP cleavage, and caspase-3 and -9 cleavage and activity were apparent at GI-5 to GI-30. Fas, FADD, and caspase-8 cleavage and activity were unaltered. Irreversible inhibition of caspase-3 and -9 activity significantly decreased ( P < 0.05) infarct size at GI-25 and GI-30 but had no effect on LVPDP or SS. Myocardial injury results from a significant increase in both necrosis and apoptosis ( P < 0.05 vs. Control group) evident by TUNEL, TTC staining, and caspase activity at GI-20. Intrinsic proapoptotic activation is evident early during ischemia but does not significantly contribute to infarct size before GI-25. The contribution of necrosis to infarct size at GI-20, GI-25, and GI-30 is significantly greater than that of apoptosis. Apoptosis is significantly decreased by caspase inhibition during early reperfusion, but this protection does not improve immediate postischemic functional recovery. caspase; myocardium Address for reprint requests and other correspondence: J. D. McCully, Div. of Cardiothoracic Surgery, Beth Israel Deaconess Medical Center, Harvard Institutes of Medicine, 77 Ave. Louis Pasteur, Rm. 144, Boston, MA 02115 (E-mail: james_mccully{at}hms.harvard.edu ).