Duarte J, Pérez O, Zarzuelo A, Jiménez J, Pérez-Vizcaíno F, Tamargo J
Department of Pharmacology, School of Pharmacy, University of Granada, Spain.
Planta Med. 1993 Aug;59(4):318-22. doi: 10.1055/s-2006-959690.
The effects of oleuropeoside were studied on the electromechanical properties of isolated guinea-pig atria. In spontaneously beating right atria, oleuropeoside decreased the amplitude of contractions (IC50 = 1.3 +/- 0.2 x 10(-4) M), slightly decreased atrial rate, and lengthened sinus node recovery time. Oleuropeoside also inhibited peak contractile force in electrically driven left atria incubated in normal (IC50 = 1.5 +/- 0.5 x 10(-4) M) and in 27 mM K+ Tyrode solution (IC50 = 1.7 +/- 0.4 x 10(-4) M). These negative inotropic effects were not accompanied by significant changes in the characteristics of action potentials recorded in atria incubated in either normal or depolarizing solutions. These results indicate that oleuropeoside produced an electromechanical uncoupling that cannot be attributed to an inhibitory effect on Ca2+ entry through L-type channels. Therefore, the negative inotropic effect may reflect an action of oleuropeoside perhaps at an intracellular level.
研究了橄榄苦苷对离体豚鼠心房机电特性的影响。在自发搏动的右心房中，橄榄苦苷降低收缩幅度（IC50 = 1.3 +/- 0.2 x 10(-4) M），轻微降低心房率，并延长窦房结恢复时间。橄榄苦苷还抑制在正常（IC50 = 1.5 +/- 0.5 x 10(-4) M）和27 mM K+ Tyrode溶液（IC50 = 1.7 +/- 0.4 x 10(-4) M）中孵育的电驱动左心房的峰值收缩力。这些负性肌力作用在正常或去极化溶液中孵育的心房中记录的动作电位特征方面未伴有显著变化。这些结果表明，橄榄苦苷产生了一种机电解偶联，这不能归因于对通过L型通道的Ca2+内流的抑制作用。因此，负性肌力作用可能反映了橄榄苦苷或许在细胞内水平的一种作用。
