Antonaccio M J, Taylor D G
Eur J Pharmacol. 1977 Apr 21;42(4):331-8. doi: 10.1016/0014-2999(77)90166-2.
Methysergide (1 and 3 mg/kg i.v.) caused dose-dependent reductions in blood pressure and heart rate of anesthetized cats. In addition, sympathetic nerve discharges of the postganglionic renal nerve were also markedly reduced by the same doses of drug. Pressor responses to electrical stimulation of the diencephalon were inhibited by 3 mg/kg but not 1 mg/kg of methysergide. These results suggest that methysergide acts to decrease blood pressure by a centrally mediated reduction in sympathetic nervous outflow and, at higher doses, can additionally prevent pressor changes caused by electrical activation of suprabulbar central structures. These results are in agreement with previous reports that methysergide has little or no peripheral effects on the cardiovascular system.
甲基麦角新碱（静脉注射1毫克/千克和3毫克/千克）可使麻醉猫的血压和心率出现剂量依赖性降低。此外，相同剂量的药物也可显著降低节后肾神经的交感神经放电。3毫克/千克的甲基麦角新碱可抑制对间脑电刺激的升压反应，但1毫克/千克则无此作用。这些结果表明，甲基麦角新碱通过中枢介导的交感神经传出减少来降低血压，且在较高剂量时，还可额外防止由延髓以上中枢结构电激活引起的升压变化。这些结果与之前关于甲基麦角新碱对心血管系统几乎没有外周作用的报道一致。
