TY - JOUR
T1 - Borderzone Contractile Dysfunction Is Transiently Attenuated and Left Ventricular Structural Remodeling Is Markedly Reduced Following Reperfused Myocardial Infarction in Inducible Nitric Oxide Synthase Knockout Mice
AU - Gilson, Wesley D.
AU - Epstein, Frederick H.
AU - Yang, Zequan
AU - Xu, Yaqin
AU - Prasad, Konkal Matt R
AU - Toufektsian, Marie Claire
AU - Laubach, Victor E.
AU - French, Brent A.
PY - 2007/10/30
Y1 - 2007/10/30
N2 - Objectives: We sought to determine the effect of inducible nitric oxide synthase (iNOS) expression on regional contractile function and left ventricular (LV) remodeling after reperfused myocardial infarction (MI). Background: Inducible nitric oxide synthase is known to contribute to global LV dysfunction after a large MI, but the mechanisms underlying this dysfunction remain unclear. Methods: We used immunohistochemistry to investigate the distribution of iNOS expression in wild-type (WT) and iNOS knockout (KO) mice early (day 1) and late (day 28) after reperfused MI. We also used serial cardiac magnetic resonance imaging at baseline and at 1, 7, and 28 days after MI to assess LV volumes, ejection fraction (EF), regional circumferential strain (Ecc), and day 1 infarct size. Results: At baseline, LV volumes and EF were similar between groups. Day 1 infarct size was also similar between groups. Immunohistochemistry revealed that iNOS expression was abundant throughout the heart in WT mice on day 1 after MI, particularly near the infarct borderzone. On day 7 after MI, Ecc in KO mice was significantly improved in some borderzone sectors compared with WT. The LV volumes were significantly lower in KO mice at days 7 and 28 compared with WT. The EF on days 7 and 28 was significantly higher in KO mice compared with WT. The circumferential extent of wall thinning was also significantly reduced in KO versus WT mice at days 7 and 28. Conclusions: Expression of iNOS contributes importantly to post-infarction contractile dysfunction and subsequent LV remodeling, suggesting new strategies to combat heart failure resulting from large MI.
AB - Objectives: We sought to determine the effect of inducible nitric oxide synthase (iNOS) expression on regional contractile function and left ventricular (LV) remodeling after reperfused myocardial infarction (MI). Background: Inducible nitric oxide synthase is known to contribute to global LV dysfunction after a large MI, but the mechanisms underlying this dysfunction remain unclear. Methods: We used immunohistochemistry to investigate the distribution of iNOS expression in wild-type (WT) and iNOS knockout (KO) mice early (day 1) and late (day 28) after reperfused MI. We also used serial cardiac magnetic resonance imaging at baseline and at 1, 7, and 28 days after MI to assess LV volumes, ejection fraction (EF), regional circumferential strain (Ecc), and day 1 infarct size. Results: At baseline, LV volumes and EF were similar between groups. Day 1 infarct size was also similar between groups. Immunohistochemistry revealed that iNOS expression was abundant throughout the heart in WT mice on day 1 after MI, particularly near the infarct borderzone. On day 7 after MI, Ecc in KO mice was significantly improved in some borderzone sectors compared with WT. The LV volumes were significantly lower in KO mice at days 7 and 28 compared with WT. The EF on days 7 and 28 was significantly higher in KO mice compared with WT. The circumferential extent of wall thinning was also significantly reduced in KO versus WT mice at days 7 and 28. Conclusions: Expression of iNOS contributes importantly to post-infarction contractile dysfunction and subsequent LV remodeling, suggesting new strategies to combat heart failure resulting from large MI.
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U2 - 10.1016/j.jacc.2007.07.047
DO - 10.1016/j.jacc.2007.07.047
M3 - Article
C2 - 17964046
AN - SCOPUS:35348963021
SN - 0735-1097
VL - 50
SP - 1799
EP - 1807
JO - Journal of the American College of Cardiology
JF - Journal of the American College of Cardiology
IS - 18
ER -