Long-term effects of B-type natriuretic peptide infusion after acute myocardial infarction in a rat model.
BACKGROUND
The effects of exogenous B-type natriuretic peptide (BNP) on postmyocardial infarction (MI) are not known. We tested the hypothesis that in vivo infusion of BNP would improve cardiac function and affect left ventricular (LV) remodeling in an experimental model of MI.


METHODS
MI was induced by coronary ligation in rats and confirmed by echocardiography. 19 rats were randomized to 1 of 3 groups: sham (n = 7), MI + saline (n = 5), MI + BNP (400 ng.kg(-1).minute(-1)) (n = 7). Infusions were delivered for 7 days via venous catheters tunneled to an infusion pump. Rats were followed for 8 weeks. Echocardiography, hemodynamics, histology, and in vivo and ex vivo pressure-volume relationships were examined.


RESULTS
LV systolic pressure, LV dP/dtmax, and infarct size improved with BNP treatment versus control MI group (132 +/- 4 vs.110 +/- 2 mm Hg, 8097 +/- 317 vs. 5816 +/- 378 mm Hg/s, 19.3% +/- 1.6% vs. 23.3% +/- 1.9%, respectively; all P < 0.05). Ex vivo end-diastolic pressure-volume relationship demonstrated reduced diastolic dysfunction after BNP therapy (P < 0.05 vs. control MI). Serum BNP levels confirmed delivery of BNP.


CONCLUSIONS
We demonstrate beneficial effects on LV function and decreased LV remodeling with BNP infusion in an experimental model of acute MI.
George
Isaac
I
Department of Surgery, Division of Cardiothoracic Surgery, Columbia University College of Physicians and Surgeons, New York, NY, USA.
Xydas
Steve
S
Klotz
Stefan
S
Hay
Ilan
I
Ng
Chuck
C
Chang
Jonathan
J
Xu
Kai
K
Li
Zhihe
Z
Protter
Andrew A
AA
Wu
Ed X
EX
Oz
Mehmet C
MC
Wang
Jie
J
D000818:Animals; D004195:Disease Models, Animal; D004452:Echocardiography; D009203:Myocardial Infarction / Q000188:drug therapy* / Q000503:physiopathology; D045283:Natriuretic Agents / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000494:pharmacology*; D020097:Natriuretic Peptide, Brain / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000494:pharmacology*; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D016277:Ventricular Function, Left / Q000187:drug effects; D020257:Ventricular Remodeling / Q000187:drug effects*
D045283:Natriuretic Agents; D020097:Natriuretic Peptide, Brain