Inotropic Response of the Myocardium in Rats with Postinfarction Cardiosclerosis Exposed to Extrasystolic Treatment

Abstract

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.

Effect of stress-proteins on survival of bone marrow mesenchymal stem cells after intramyocardial transplantation against the background of postinfarction heart remodeling

“…According to published reports and our data ( Fig. 1), dead cardiomyocytes are replaced with the connective tissue and a scar is formed in the zone of necrosis 40 days after this procedure; heart hypertrophy develops [4].…”

“…Experiments were carried out on male Wistar rats weighing 180-230 g. Damage to the myocardium was induced by coronary occlusion [4]. The thorax and the pericardium were opened under light ether anesthesia and a ligature was applied on the upper third of the left descending coronary artery.…”

“…The optimal volume of the cell suspension for seeding into 50-ml culture flasks was determined. The volume of cell suspension was brought to 5 ml with culture medium and incubated routinely for 16 days [4]. The medium was then removed, the flasks were dried, and their content was fixed and stained.…”

Changes in the Rhythmoinotropic Dependence of the Myocardium in Rats with Postinfarction Cardiosclerosis after β1-Adrenoreceptor Blocking

“…2). Our previous studies [1] showed that the rat cardiomyocyte excitability reduced in PICS, the PEC amplitude not depending on the degree of extrasystolic contraction. Our present findings indicate that muscle strips from postinfarction myocardium do not react to extrasystolic exposure by potentiation.…”

Radiofrequency Ablation as a Possible Method for Preparing Pathologically Altered Myocardium for Intramyocardial Cell Transplantation

“…On day 45 after coronary occlusion, postinfarction cardiosclerosis (PICS) developed. Similar coronary occlusion procedure was described elsewhere [3,8].…”