Digitoxin Prolongs Survival of Female Rats With Heart Failure Due to Large Myocardial Infarction

Características fisiopatológicas do modelo de insuficiência cardíaca pós-infarto do miocárdio no rato

“…The electrocardiogram 2 and the echocardiogram [3][4][5][6][7][8][9][10][11][12][13][14][15] are noninvasive methods capable of identifying the area of necrosis or scarring. Although it identifies the presence of an MI-dependent electrically inactive area, the ECG is not a method that can quantify the infarction area 2 .…”

“…Although it identifies the presence of an MI-dependent electrically inactive area, the ECG is not a method that can quantify the infarction area 2 . The echocardiogram can determine the presence and the size of the MI with very good sensitivity [3][4][5][6][7][8][9][10][11][12][13][14][15] , even in periods as early as two days after necrosis, and it also provides information about deviant atrial and ventricular function. The best method for post-mortem diagnosis of MI depends on the stage in which the autopsy occurs.…”

Remodelamento miocárdico após grandes infartos converte potenciação pós-pausa em decaimento da força em ratos

“…Tissue homogenates were analyzed by Western blotting according to previously described protocols 5 to compare the protein expression of SERCA2, phospholamban (PLB), phosphoSer 16 -PLB and NCX in all experimental groups. Samples of noninfarcted myocardium were rapidly frozen at -70 o C. Tissues were homogenized in ice-cold extraction buffer (Tris 50 mM, EDTA 1 mM and sacarose 250 mM, pH 7.4) using Polytron (Polytron® PT2100, Kinematica AG, Littau, LU, SWI).…”

“…Then the membrane was blocked for 60 min at room temperature in Tris-buffered solution (Tris 10 mM, NaCl 100 mM, Tween-20 0.1%, pH 7.4) with 5% powdered non-fat milk. Next, the membrane was incubated overnight at 4°C with anti-NCX1 rat monoclonal antibodies (1:1500 dilution, Swant® Swiss antibodies, Bellinzona, CH, SWI), anti-SERCA2 rat monoclonal antibodies (1:2500 dilution, Abcam Inc., MA, USA), anti-PLB rat monoclonal antibodies (0.25 µg/ml, Upstate Biotechnology, Lake Placid, NY, USA) or anti-phospho-Ser 16 -PLB rat monoclonal antibodies (1:1000, Upstate Biotechnology, Lake Placid, NY, USA). After washing, the membrane was incubated for 90 min with an anti-rat IgG antibody combined with horseradish peroxidase (1:3000 dilution; Bio-Rad, CA, USA).…”

“…Previous reports described reduction of the post-rest potentiation in left ventricular papillary muscles from rats with healed MI of different infarct sizes 9,10 . Recently, we identified, for the first time, decay of the post-rest contractions in rats with chronic heart failure 16 . Since the pathophysiological mechanisms underlying the genesis of post-rest contraction in the rat myocardium after remodeling are not completely defined, in this report, we investigated the PRC of left ventricular papillary muscle derived from the MI, and its relationship with the molecular remodeling of the primary Ca 2+ -handling proteins.…”