Wang R, Moreau P, Deschamps A, de Champlain J, Sauvé R, Foucart S, Bai L, Lu X R
Département de Physiologie, Faculté de Médecine, Université de Montréal, Québec, Canada.
Toxicon. 1994 Feb;32(2):191-200. doi: 10.1016/0041-0101(94)90108-2.
Buthus martensii (Karsch) (BMK) scorpion envenomation is a common medical problem in China and BMK scorpion has been widely used in traditional Chinese medicine. However, the cardiovascular effects of this venom have not been systematically investigated. In the present study, i.v. BMK venom injection significantly increased the blood pressure in conscious rats in a concentration-dependent manner (ED50 = 59 +/- 12 micrograms/kg). The increase in blood pressure occurred within 1 min of injection of the venom and was sustained for more than 50 min. Heart rate was not changed by the venom in conscious rats. In vitro studies with BMK venom revealed the increase in the force of contraction, without modification of the contraction frequency (within 20 min) of isolated atrial strips. Contractions of isolated arterial strips from aorta, renal and vertebral arteries were also enhanced by BMK venom with a time lag of 8 min between the application of the venom and the initiation of the contraction. Furthermore, BMK venom-induced rises in blood pressure in vivo and increased contraction of isolated vessel strips were inhibited by prazosin and tolazoline, respectively, two alpha 1-adrenergic antagonists. BMK venom alone did not alter intracellular calcium concentrations, [Ca2+]i, in cultured vascular smooth muscle cells and endothelial cells. However, BMK venom significantly increased the metabolism of InsP3 in dispersed cardiac myocytes, indicating a direct effect on cardiac myocytes. These results demonstrate the significant cardiovascular effects of BMK venom, which may be mediated by an alteration in InsP3 in cardiac myocytes but not by [Ca2+]i in vascular smooth muscle cells.
东亚钳蝎（Buthus martensii (Karsch)，简称BMK）蛰伤是中国常见的医学问题，且东亚钳蝎已被广泛应用于传统中药。然而，这种毒液对心血管系统的影响尚未得到系统研究。在本研究中，静脉注射BMK毒液可使清醒大鼠的血压以浓度依赖的方式显著升高（半数有效剂量[ED50]=59±12微克/千克）。注射毒液后1分钟内血压升高，并持续超过50分钟。清醒大鼠的心率不受毒液影响。对BMK毒液的体外研究显示，离体心房肌条的收缩力增强，而收缩频率在20分钟内未改变。主动脉、肾动脉和椎动脉的离体动脉条收缩也因BMK毒液而增强，毒液施加与收缩开始之间有8分钟的时间延迟。此外，体内BMK毒液引起的血压升高和离体血管条收缩增加分别被两种α1肾上腺素能拮抗剂哌唑嗪和妥拉唑啉抑制。单独的BMK毒液不会改变培养的血管平滑肌细胞和内皮细胞内的钙浓度[Ca2+]i。然而，BMK毒液显著增加了分散心肌细胞中肌醇三磷酸（InsP3）的代谢，表明对心肌细胞有直接作用。这些结果证明了BMK毒液对心血管系统有显著影响，这可能是由心肌细胞中InsP3的改变介导的，而不是由血管平滑肌细胞中的[Ca2+]i介导的。
