Perren M J, Feniuk W, Humphrey P P
Pharmacology Division, Glaxo Group Research Ltd, Ware, Hertfordshire, UK.
Cephalalgia. 1989;9 Suppl 9:41-6. doi: 10.1111/J.1468-2982.1989.TB00071.X.
The haemodynamic effects of the selective 5-HT1-like agonist GR43175 have been compared with that of ergotamine in anaesthetized cats. Both GR43175 (30-1000 micrograms/kg intravenously) and ergotamine (0.3-30 micrograms/kg intravenously) caused a dose-dependent reduction in the proportion of cardiac output passing through arteriovenous anastomoses (AVAs). However, unlike GR43175, the effect of ergotamine (30 micrograms/kg intravenously) was associated with marked increases in diastolic blood pressure and total peripheral resistance. In further studies, the effect of GR43175 on the distribution of blood flow within the carotid bed has been examined. GR43175 caused a reduction in total carotid arterial blood flow which was entirely due to a reduction in flow through carotid AVAs. These results demonstrate that GR43175, unlike ergotamine, has a highly selective vasoconstrictor action on AVAs within the cranial circulation of anaesthetized cats. Such a mechanism may be important in its antimigraine activity.
在麻醉猫身上，已将选择性5-羟色胺1样激动剂GR43175的血流动力学效应与麦角胺的效应进行了比较。GR43175（静脉注射30 - 1000微克/千克）和麦角胺（静脉注射0.3 - 30微克/千克）均引起通过动静脉吻合支（AVA）的心输出量比例呈剂量依赖性降低。然而，与GR43175不同，麦角胺（静脉注射30微克/千克）的作用伴有舒张压和总外周阻力的显著升高。在进一步的研究中，已检测了GR43175对颈动脉床内血流分布的影响。GR43175导致总颈动脉血流减少，这完全是由于通过颈动脉AVA的血流减少所致。这些结果表明，与麦角胺不同，GR43175对麻醉猫颅循环内的AVA具有高度选择性的血管收缩作用。这种机制在其抗偏头痛活性中可能很重要。
