Treatment with the selective B2 receptor agonist NG291 for 1 week post-myocardial infarction in mice improved ejection fraction compared to saline (69% vs. 61%, P=0.01).
Does NG291 improve cardiac function and reduce tissue damage in mice post-acute myocardial infarction?
In a mouse model of acute MI, a selective B2 receptor agonist improved ejection fraction and reduced myocyte apoptosis and inflammatory gene expression.
Absolute Event Rate: 69% vs 61%
p-value: p=0.01
BACKGROUND: The cardioprotective benefits of bradykinin are attributable to activation of its B(2) receptor (B(2)R)-mediated actions and abolished by B(2)R antagonists. The current experiments evaluated the cardioprotective potential of a potent, long-acting B(2)R-selective agonist peptide analogue of bradykinin, the compound NG291. METHODS: We compared the extent of cardiac tissue damage and remodeling and expression pattern of selected genes in mice submitted to acute myocardial infarct (MI) and treated for 1 week with either NG291 Hyp(3),Thi(5),(N)Chg(7),Thi(8)-bradykinin or with saline delivered via osmotic minipump. RESULTS: Active treatment resulted in better ejection fraction (EF) 69 +/- 1% vs. 61 +/- 3.1% (P = 0.01), (vs. 85 +/- 1.3% in sham-operated controls), fractional shortening (FS) 38 +/- 4% vs. 32 +/- 8% (NS) (vs. 53 +/- 1.2 in sham-operated controls), and fewer markers of myocyte apoptosis (TUNEL-positive nuclei 4.9 +/- 1.1% vs. 9.7 +/- 0.03%, P = 0.03). Systolic blood pressure (SBP) at end point was normal at 110 +/- 4.2 in actively treated mice, but tended to be lower at 104 +/- 4.7 mm Hg in saline controls with decreased cardiac systolic capacity. Expression patterns of selected genes to factors related to tissue injury, inflammation, and metabolism (i.e., the B(1)R, B(2)R, endothelial nitric oxide synthase (eNOS), TNF-alpha, cardiomyopathy-associated 3 (Cmya3), and pyruvate dehydrogenase kinase isoenzyme 4 (PDK4)) showed that acute MI induced significant upregulation of these genes, and active treatment prevented or attenuated this upregulation, whereas the B(2)R agonist itself produced no difference in the myocardium of sham-operated mice. CONCLUSIONS: Treatment with a selective B(2)R agonist initiated at the time of induction of acute MI in mice had a beneficial effect on cardiac function, tissue remodeling, and inflammation-related tissue gene expression, which may explain its structural and functional benefits.
Marketou et al. (2010) studied Acute myocardial infarct. NG291 (selective B2 receptor agonist) vs. Saline was evaluated on Ejection fraction (EF) (p=0.01). Treatment with the selective B2 receptor agonist NG291 for 1 week post-myocardial infarction in mice improved ejection fraction compared to saline (69% vs. 61%, P=0.01).