Yu J, Hu W S
Department of Pharmacology, Tongji Medical University, Wuhan 430030.
Yao Xue Xue Bao. 1997;32(1):1-4.
Neferine (Nef), a hypotensive agent with antiarrythmic action, is a dibenzyl isoquinoline alkaloid isolated from a Chinese medicinal herb (Nelumbo nucifera Gaertn). Its effects on platelet aggregation and TXA2/PGI2 and cAMP/cGMP balance were studied with methods of turbidimetry and RIA. Nef was shown to significantly inhibit rabbit platelet aggregation induced by ADP, collagen, arachidonic acid (AA) and platelet-activating factor (PAF) with IC50 of 16, 22, 193 and 103 mumol.L-1, respectively. Nef was found to increase vascular 6-keto-PGF1 alpha and platelet cAMP levels in dose-dependent manner, but inhibit AA stimulated TXA2 release from platelets. Nef showed no significant effect on the platelet cGMP level. The results suggest that the mechanism of Nef on platelet aggregation is related to regulation of TXA2/PGI2 and cAMP/cGMP balance.
甲基莲心碱（Nef）是一种具有抗心律失常作用的降压药，是从一种中草药（莲Nelumbo nucifera Gaertn）中分离得到的二苄基异喹啉生物碱。采用比浊法和放射免疫分析法研究了其对血小板聚集及血栓素A2/前列环素（TXA2/PGI2）和环磷酸腺苷/环磷酸鸟苷（cAMP/cGMP）平衡的影响。结果表明，Nef能显著抑制由二磷酸腺苷（ADP）、胶原、花生四烯酸（AA）和血小板活化因子（PAF）诱导的兔血小板聚集，其半数抑制浓度（IC50）分别为16、22、193和103μmol·L-1。Nef能剂量依赖性地增加血管6-酮-前列环素F1α（6-keto-PGF1α）和血小板cAMP水平，但抑制AA刺激的血小板TXA2释放。Nef对血小板cGMP水平无显著影响。结果提示，Nef抑制血小板聚集的机制与调节TXA2/PGI2和cAMP/cGMP平衡有关。
