Abramochkin, Denis V. published the artcileA characterization of the electrophysiological properties of the cardiomyocytes from ventricle, atrium and sinus venosus of the snake heart, Related Products of pyridine-derivatives, the main research area is acetylcholine atrium ventricle sinus venosus cardiomyocyte Python; Acetylcholine; Action potential; Heart; Ionic current; Pacemaker; Python molurus; Reptile; Sinus venosus.
A detailed description of the electrophysiol. features of cardiomyocytes in the various contractile chambers of the vertebrate heart is essential to understand the evolution of cardiac elec. activity, yet very little is known about reptiles. The present study characterizes major ionic currents (INa, ICaL, IKr, IK1 and IKACh) and action potential (AP) configuration in cardiomyocytes from the ventricle, the right atrium and the sinus venosus (SV) of Burmese pythons (Python molurus) using sharp microelectrode and patch clamp recordings. Special attention was given to SV, since it consists of myocardial cells and appears to contribute to right atrial filling in snakes. We demonstrate that most of the SV in pythons has a stable resting potential of – 82.3 ± 2.6 mV (n = 9) and lacks pacemaker activity. AP duration at 50% repolarization was similar in cells from SV and atria (350.2 ± 8.7 and 330.4 ± 17.2 ms, resp.; n = 7), but shorter than ventricular APs (557.6 ± 19.2 ms, n = 5) at 30°C. The densities of ionic currents, however, differed substantially between atrial and SV cells, where the latter had much lower densities of INa, ICaL and IKr than atrial and ventricular myocytes. IK1 in ventricle was ninefold greater than in atrial cells and 23-fold greater than in myocytes from SV. However, IKACh was absent in ventricular cells, while it was equally large in atrial and SV myocytes. Consistent with this observation, APs of atrium and SV, but not ventricle, were greatly shortened upon addition of acetylcholine (10-6 M). Thus, snake SV, right atrium and ventricle have distinct patterns of ionic currents, but the resulting elec. activity is similar in atrium and SV.
Journal of Comparative Physiology, B: Biochemical, Systems, and Environmental Physiology published new progress about Cardiomyocyte. 21829-25-4 belongs to class pyridine-derivatives, name is Dimethyl 2,6-dimethyl-4-(2-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylate, and the molecular formula is C17H18N2O6, Related Products of pyridine-derivatives.