Kecskeméti V, Stadler I, Körmöczy P
Biomed Biochim Acta. 1984;43(8-9):S287-90.
5-nitro-PGI1 is a selective vasodilatory analogue of prostacyclin which has not antiaggregatory potency. We examined the hemodynamics, antiaggregatory and electrophysiological effects of 5-nitro-PGI1, comparing them with those of PGI2-Na and nitroglycerin (NG). In anaesthetized open-chest cat and dog, PGI2-Na, 5-nitro-PGI1 and NG reduced the mean blood pressure (BP), BPsyst, BPdiast, left ventricular pressure, dp/dtmax, coronary resistance, while their effect on heart rate, on cardiac output was inconsistent. ED50 values of BP lowering effect of PGI2-Na, 5-nitro-PGI1 and NG were 4.6 X 10(-10), 3.9 X 10(-10) and 6 X 10(-10)(M), respectively. IC50 values on ADP (10 microM) induced aggregation in rabbit platelet rich plasma of PGI2-Na, 5-nitro-PGI1 and NG were 5 X 10(-9), 3.5 X 10(-4), 3.75 X 10(-3) (M), respectively. The transmembrane action potential (AP) characteristics were not changed significantly by 10(-6)M 5-nitro-PGI1. Higher concentrations (10(-5), 10(-6)M) slightly reduced the resting potential (RP) and maximum rate of rise (Vmax) of AP and shortened AP duration. NG in 10(-6)M caused a slight hyperpolarization, while higher concentrations (10(-5), 10(-4)M) shortened only AP duration. PGI2-Na in all concentration studied (1.6 X 10(-6) -10(-4)M) caused a slight hyperpolarization, increased potently Vmax but shortened AP duration only in high concentration. The results show that 5-nitro-PGI1 exerted the same hemodynamic effect as PGI2-Na and NG; practically failed to exert antiaggregatory activity; and had similar electrophysiological effects to NG.
5-硝基前列环素1是前列环素的一种选择性血管舒张类似物，无抗聚集活性。我们研究了5-硝基前列环素1的血流动力学、抗聚集及电生理效应，并与前列环素2钠和硝酸甘油（NG）进行比较。在麻醉开胸猫和犬中，前列环素2钠、5-硝基前列环素1和NG均降低平均血压（BP）、收缩压、舒张压、左心室压力、dp/dtmax、冠状动脉阻力，而它们对心率和心输出量的影响不一致。前列环素2钠、5-硝基前列环素1和NG降低血压作用的ED50值分别为4.6×10⁻¹⁰、3.9×10⁻¹⁰和6×10⁻¹⁰（M）。前列环素2钠、5-硝基前列环素1和NG对兔富血小板血浆中ADP（10微摩尔）诱导的聚集的IC50值分别为5×10⁻⁹、3.5×10⁻⁴、3.75×10⁻³（M）。10⁻⁶M的5-硝基前列环素1对跨膜动作电位（AP）特征无明显改变。较高浓度（10⁻⁵、10⁻⁶M）可轻微降低AP的静息电位（RP）和最大上升速率（Vmax），并缩短AP持续时间。10⁻⁶M的NG引起轻微超极化，而较高浓度（10⁻⁵、10⁻⁴M）仅缩短AP持续时间。在所研究的所有浓度（1.6×10⁻⁶ - 10⁻⁴M）下，前列环素2钠引起轻微超极化，显著增加Vmax，但仅在高浓度时缩短AP持续时间。结果表明，5-硝基前列环素1具有与前列环素2钠和NG相同的血流动力学效应；几乎不具有抗聚集活性；并且具有与NG相似的电生理效应。
