【摘要】 目的：研究洛土辛（ Ｌｏｔ） 对血管收缩功 能及血小 板环核苷 酸含量的 影响。方 法：采用 血管收 缩张力记录和放射免疫测 定法。结 果： Ｌｏｔ 、罂 粟碱（ Ｐａｐ） 和 氨力 农（ Ａｍ ） ０３ ～１００ μｍ ｏｌ／ Ｌ 可剂 量依 赖地 松 弛５ Ｈ Ｔ３０ μｍ ｏｌ／ Ｌ 诱发的血管的收 缩反应， Ｌｏｔ 对大鼠主动脉、犬隐静脉和猪冠状 动脉松弛作用的 负对数摩尔浓度 Ｅ Ｄ５０分别为５５ ，５４ ，５２ ， Ｐａｐ 对前两者的 Ｅ Ｄ５０ 分别为５３ ，５６ ， Ａｍ 对前者的 Ｅ Ｄ５０ 为５４ ；美蓝使它们松弛血 管的作用量效曲线右移。 Ｌｏｔ 和 Ａｍ 还增加异丙肾上腺素松弛 大鼠主动脉的作用。 Ｌｏｔ 拮抗 Ｍｅｔｈ 激动α受体引起的大鼠主动脉血管收缩反应的ｐ Ａ２ 值仅为４６ 。 Ｌｏｔ １０ 、１００ μｍ ｏｌ／ Ｌ 可显著地提高血小板内ｃ Ａ Ｍ Ｐ 含量，略升ｃ Ｇ Ｍ Ｐ。结论： Ｌｏｔ 有舒张血管、提高血小板环核苷酸作用 ，此可 能与磷酸二酯酶抑制有关。更多还原

【Abstract】 AIM:To study the effects of Lotusine (Lot), a pure alkaloid extracted from the green seed embryo of Nelumbo nucifera Gaertn , on the contractions of blood vessals and platelet cyclic nucleotides. METHODS: Recording of contractile force of blood vessels and radioimmunoassay were used. RESULTS: Lot, Papaverine (Pap) and Amrinone (Am) 0.3～100μmol/L could dose dependently relax blood vessels contracted with 5 hydroxytryptamine (5 HT) 30μmol/L. The negative log ED 50 of Lot on isolated rat aortic strips, canine saphenous veins and pig coronary arteries were 5.5, 5.4 and 5.2 respectively. The ED 50 of Pap on the former two were 5.3 and 5.6 respectively and that of Am on the former was 5.4. Moreover, methylene blue could shift the dose response curve of Lot to the right. Lot could enhance the relaxation response to lsoprenaline in the preparation precontracted with KCl 30mmol/L. Lot parallelly shift the dose response curve of methoxamine to the right with the pA 2 value of 4.7. Lot 10,100μmol/L obviously increased the platelet cAMP with 26% and 43% respectively and slightly increased the cGMP with 11% and 16% respectively. Conclusion:The results suggest that Lot has relaxation effect on blood vessels and increasing effect of cycllic nucleotides on platelet, which may be related to inhibition of phosphodiesterase.更多还原