Nebivolol prevents remodeling in a rat myocardial infarction model: an echocardiographic study.
OBJECTIVE
Ventricular remodeling (VR) which develops after myocardial infarction (MI) plays an important role in progressive left ventricular dysfunction. We aimed to investigate the role of nebivolol treatment on VR after a MI in a rat ischemia-reperfusion model.


METHODS
Rats were divided into 3 groups of 12 each: sham operated (sham-control), MI-induced (MI-control) and nebivolol treated (MI-nebivolol). Left ventricular (LV) diameters, volumes, and diastolic filling parameters were evaluated by echocardiography. On the 28th day, after recording the systemic and LV pressures and determining the plasma nitric oxide (NO) and peroxynitrite (ONOO-) levels , animals were sacrificed and heart, body and LV weights (HW, BW, LVW) were measured and infarct sizes were determined. Results were evaluated statistically by ANOVA for repeated measurements 3x3 factorial design with post-hoc Bonferroni test.


RESULTS
After MI, while VR (an increase in LV diameters and volumes associated with a decrease in EF, FS and posterior wall thickness change (LWPc) was significant in MI-control rats (p<0.05 for; all comparisons) these changes were significantly less in MI-nebivolol group (p=0.08 and p=0.06 for EF and FS respectively). LV end diastolic pressure (LVEDP) was lower (p<0.005) and Delta+/- dp/dt's (p<0.05) were higher in MI-nebivolol group compared to MI-control animals. Although infarct sizes were similar in MI-induced groups (p=0.79); LVW/HW and HW/BW's were significantly greater in the MI-control group compared to sham-control (p<0.01 for all comparisons), these changes were not statistically significant in MI-nebivolol group. The increase in plasma NO and ONOO- levels were also prevented with nebivolol.


CONCLUSIONS
Nebivolol therapy reduced the effects of VR in rats after MI. These beneficial effects were not related to its heart rate and blood pressure reducing effects. Nitric oxide regulatory action of this compound may contribute these beneficial effects on VR developed after MI.
Mercanoğlu
Güldem Olguner
GO
Department of Pharmacology, Faculty of Pharmacy, Yeditepe University, Istanbul, Turkey. guldemiko@yahoo.com
Pamukçu
Burak
B
Safran
Nurhas
N
Mercanoğlu
Fehmi
F
Fici
Francesco
F
Güngör
Mehmet
M
D000818:Animals; D001578:Benzopyrans / Q000627:therapeutic use*; D001794:Blood Pressure / Q000187:drug effects; D004195:Disease Models, Animal; D004452:Echocardiography / Q000379:methods; D004983:Ethanolamines / Q000627:therapeutic use*; D006801:Humans; D009203:Myocardial Infarction / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000473:pathology; D000068577:Nebivolol; D051381:Rats; D017207:Rats, Sprague-Dawley; D014665:Vasodilator Agents / Q000627:therapeutic use*; D020257:Ventricular Remodeling / Q000187:drug effects*
D001578:Benzopyrans; D004983:Ethanolamines; D014665:Vasodilator Agents; D000068577:Nebivolol