Inotropic response of the myocardium in rats with postinfarction cardiosclerosis exposed to extrasystolic treatment.
The inotropic response of the myocardium to extrasystolic treatment was studied on isolated perfused papillary muscles from rats with postinfarction cardiosclerosis. The development of postinfarction cardiosclerosis was accompanied by a decrease in myocardial excitability. The amplitude of extrasystolic contractions in the remodeled myocardium far surpassed the control. However, the amplitude of postextrasystolic contraction did not surpass that in normal contraction-relaxation cycle. Our results suggest that the ability of the sarcoplasmic reticulum in cardiomyocytes to accumulate Ca2+ is impaired during postinfarction remodeling.
Kondrat'eva
D S
DS
Institute of Cardiology, Tomsk Research Center, Siberian Division of the Russian Academy of Medical Sciences, Tomsk, Russia. ugdina@mail.ru
Afanas'ev
S A
SA
Falaleeva
L P
LP
Shakhov
V P
VP
D000818:Animals; D000889:Anti-Arrhythmia Agents / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism; D004558:Electric Stimulation; D006352:Heart Ventricles / Q000378:metabolism; D007537:Isometric Contraction / Q000187:drug effects*; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects*; D017202:Myocardial Ischemia / Q000209:etiology / Q000378:metabolism / Q000503:physiopathology*; D009206:Myocardium / Q000378:metabolism*; D032383:Myocytes, Cardiac / Q000378:metabolism; D010210:Papillary Muscles / Q000502:physiology; D010477:Perfusion; D051381:Rats; D017208:Rats, Wistar; D012519:Sarcoplasmic Reticulum / Q000378:metabolism; D013599:Systole
D000889:Anti-Arrhythmia Agents; D002118:Calcium