Chronic therapy with nipradilol, a beta-adrenergic blocker, attenuated left ventricular remodeling following myocardial infarction in rats.
We determined whether chronic treatment with nipradilol, a beta-blocker with vasodilating action, reduces left ventricular cavity dilation (LV remodeling) following myocardial infarction and improves cardiac performance. Myocardial infarction was produced by coronary artery ligation in 16-week-old female rats and then the rats were treated for 3-4 months with nipradilol (10 mg/kg/day) or vehicle (0.5% carboxymethylcellulose). The effect of nipradilol on LV remodeling was evaluated by assessing the left ventricular end-diastolic volume index (LVEDVI) and passive pressure-volume relation curve. Since LVEDVI depends on the infarct size, LVEDVI was compared between the vehicle- and nipradilol-treated rats with similar infarct size (10-40%). At 3-4 months after myocardial infarct production, the left ventricular end-diastolic volume index in the vehicle-treated rats with myocardial infarction was significantly increased, compared with that in the sham-operated rats without infarction. The nipradilol-treated rats had a significantly smaller left ventricular volume index than the vehicle-treated rats (2.04 +/- 0.16 ml/kg in the vehicle-treated group vs 1.36 +/- 0.10 ml/kg in the nipradilol-treated group, P < 0.01). The maximum cardiac index achieved by volume loading as an index of cardiac performance was significantly greater in the nipradilol group than the vehicle group (254.5 +/- 12.6 ml/min kg in the vehicle group vs 347.9 +/- 20.2 ml/min kg in the nipradilol group, P < 0.01). These results suggest that chronic treatment of nipradilol attenuated left ventricular cavity dilation after myocardial infarction and improved cardiac performance.
Sonoki
H
H
Tokyo Research Laboratories, Kowa Co., Ltd., Japan.
Nakamura
M
M
Takeshita
A
A
D000319:Adrenergic beta-Antagonists / Q000494:pharmacology / Q000627:therapeutic use*; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002302:Cardiac Output / Q000187:drug effects; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D009203:Myocardial Infarction / Q000150:complications* / Q000503:physiopathology; D011412:Propanolamines / Q000494:pharmacology / Q000627:therapeutic use*; D051381:Rats; D017208:Rats, Wistar; D018487:Ventricular Dysfunction, Left / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control*; D017725:Ventricular Pressure / Q000187:drug effects
D000319:Adrenergic beta-Antagonists; D011412:Propanolamines; C036089:nipradilol