Effects of metoprolol and ramipril on action potentials after myocardial infarction in rats.
The effects of chronic treatment with the beta-adrenoceptor antagonist metoprolol, the angiotensin converting enzyme inhibitor ramipril, their combination, or placebo on action potential configuration 6 weeks after myocardial infarction in rats were studied. Action potentials were measured in isolated left ventricular posterior papillary muscles and compared with action potentials from a sham operated group without infarction. After infarction, the action potential amplitude was reduced and this phenomenon was partially reversed by metoprolol- and ramipril-treatment. Prolonged repolarisation after infarction compared to sham operated animals was additionally delayed after metoprolol treatment. Thus, metoprolol extends the refractory period, which may counteract tachyarrhythmia.
Wagner
K
K
Institute of Physiology, Humboldt University (Charité),Tucholskystr. 2 10117, Berlin, Germany. kay-dietrich.wagner@charite.de
Kamkin
A
A
Kiseleva
I
I
Theres
H
H
Scholz
H
H
Günther
J
J
D000200:Action Potentials; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology*; D000818:Animals; D004558:Electric Stimulation; D006321:Heart / Q000503:physiopathology*; D008297:Male; D008790:Metoprolol / Q000494:pharmacology*; D009203:Myocardial Infarction / Q000503:physiopathology*; D017257:Ramipril / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar
D000319:Adrenergic beta-Antagonists; D000806:Angiotensin-Converting Enzyme Inhibitors; D008790:Metoprolol; D017257:Ramipril