Saito K, Markowitz S, Moskowitz M A
Department of Neurosurgery, Massachusetts General Hospital, Harvard Medical School, Boston 02114.
Ann Neurol. 1988 Dec;24(6):732-7. doi: 10.1002/ana.410240607.
Although the ergot alkaloids (ergots) are useful drugs for the acute treatment of migraine headaches, their mechanism of action remains obscure. When administered to rats in clinically relevant doses, ergots blocked the development of neurogenic plasma extravasation in dura mater. Plasma extravasation was induced by depolarization of perivascular axons following capsaicin injection or unilateral electrical stimulation of the trigeminal nerve. The ergot action could not be accounted for by vasoconstriction alone because neurogenic plasma leakage was not blocked by angiotensin or phenylephrine. Furthermore, ergots did not block plasma extravasation induced by administering sensory neuropeptides that mediate enhanced permeability. We propose that the therapeutic effects of ergots in vascular headaches may result from peripheral blockade of small fiber (C or A-delta)-dependent neurogenic inflammation within the dura mater.
尽管麦角生物碱（麦角）是治疗偏头痛急性发作的有效药物，但其作用机制仍不清楚。以临床相关剂量给大鼠用药时，麦角可阻断硬脑膜中神经源性血浆外渗的发生。血浆外渗是由辣椒素注射或三叉神经单侧电刺激后血管周围轴突去极化诱导的。麦角的作用不能仅用血管收缩来解释，因为血管紧张素或去氧肾上腺素不能阻断神经源性血浆渗漏。此外，麦角不能阻断由介导通透性增强的感觉神经肽给药所诱导的血浆外渗。我们认为，麦角在血管性头痛中的治疗作用可能源于硬脑膜内小纤维（C或A-δ）依赖性神经源性炎症的外周阻断。
