Zhao, Junli published the artcileBerberine mediated positive inotropic effects on rat hearts via a Ca2+-dependent mechanism, Category: pyridine-derivatives, the main research area is berberine inotropic agent heart calcium; Ca2+; Na+; berberine; heart; positive inotropic effect.
Previous studies showed that berberine, an alkaloid from Coptis Chinensis Franch, might exert a pos. inotropic effect on the heart. However, the underlying mechanisms were unclear. Here, we reported that berberine at 10-20μM increased the left ventricular (LV) developed pressure and the maximal rate of the pressure rising, and it increased the maximal rate of the pressure descending at 20μM in Langendorff-perfused isolated rat hearts. These effects diminished with the concentration of berberine increasing to 50μM. In the concentration range of 50-300μM, berberine increased the isometric tension of isolated left ventricular muscle (LVM) strips with or without elec. stimulations, and it (30-300μM) also increased the intracellular Ca2+ level in the isolated LV myocytes. The removal of extracellular Ca2+ hindered the berberine-induced increases in the tension of LVM strips and the intracellular Ca2+ level of LV myocytes. These suggested that berberine might exert its pos. inotropic effects via enhancing Ca2+ influx. The blockade of L-type Ca2+ channels (LTCCs) with nifedipine significantly attenuated 300 mM berberine-induced tension increase in LVM strips but not the increase in the intracellular Ca2+ level. Berberine (300 mM) further increased the LVM tension following the treatment with the LTCC opener FPL-64716 (10 mM), indicating an LTCC-independent effect of berberine. Lowering extracellular Na+ attenuated the berberine-induced increases in both the tension of LVM strips and the intracellular Ca2+ level of LV myocytes. In conclusion, berberine might exert a pos. inotropic effect on the isolated rat heart by enhancing the Ca2+ influx in LV myocytes; these were extracellular Na+ -dependent.
Frontiers in Pharmacology published new progress about Heart. 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, Category: pyridine-derivatives.