Papillary muscles split in the presence of 2,3-butanedione monoxime have normal energetic and mechanical properties

摘要: A number of studies have used 2,3-butanedione monoxime (BDM) to avoid myocardial damage when small muscle preparations were cut from large hearts. The present study investigates the mechanical and energetic effects varying cross-sectional area (CSA) by dissection in physiological saline containing BDM. By use adult rat hearts, three groups obtained: whole left ventricular papillary muscles (Whole) split longitudinally presence 30 mM BDM, with removal approximately 10% (BDMSP1) or 40-50% (BDMSP2) (5 animals each group). isolated studied at 27 degrees C stimulated 0.167 Hz. Whole BDMSP1 had comparable CSAs; isotonically contracting working against a range afterloads, work, enthalpy (energy use), efficiency (work/enthalpy x 100%) similar for two groups. In addition, isometric performance [e.g., developed stress (force/CSA), length-tension relationship, contraction time course] was also thinner BDMSP2 showed an enhanced compared This outcome accordance data literature documenting negative correlation between CSA. results suggest that BDM-split intact CSA properties.