CORTICOTROPIN RELEASING HORMONE INDUCED DURA MAST CELL A

已知肥大细胞参与过敏反应，其中它们分泌许多血管活性和促炎分子。肥大细胞位于血管周围，靠近神经末梢，并通过神经刺激激活。 急性心理应激引起大鼠硬脑膜肥大细胞脱颗粒，并导致脑脊液（CSF）肥大细胞蛋白酶（RMCP）I升高。 这些影响被抑制预处理与促肾上腺皮质激素释放激素（CRH）的中和抗血清，治疗与CRH受体拮抗剂Antalarmin或治疗acetamatally与辣椒素消耗感觉神经纤维的P物质（SP）的内容。 CRH及其结构类似物尿皮质素的皮内给药可使皮肤肥大细胞脱颗粒并增加血管通透性;该过程依赖于肥大细胞并由特异性CRH受体介导。 我们假设CRH直接或通过SP释放到血脑屏障（BBB）外，导致硬脑膜肥大细胞脱粒和血管舒张分子（如组胺）的释放。 这一行为有助于解释偏头痛的病理生理学，并可作为筛选相关药物的可能模型。 我们将通过以下研究来验证这一前提：（a）通过测定C57 BL/6 J小鼠硬脑膜中125 I-BSA外渗的Evans蓝来观察CRH和Urocortin对硬脑膜肥大细胞脱颗粒和血管舒张的影响;血管舒张也将通过使用设计成检测暂时血流、血容量和氧合的光纤探针来确定，而颈静脉样品将用于组胺和甲基组胺的测定;（B）在有或没有用CRH受体拮抗剂Astressin或非肽NK 1 - 1预处理的情况下，制动应激对硬脑膜肥大细胞脱粒和硬脑膜血管舒张的影响。受体拮抗剂SR 140.333;（c）在W/Wv肥大细胞缺陷小鼠中如（a-b）中那样的硬脑膜血管舒张以确定对肥大细胞的需要，在CRH敲除小鼠中检查CRH的作用，以及SP和NK 1受体敲除，这些研究将帮助我们了解在压力下释放的某些神经肽如何触发硬脑膜肥大细胞分泌，导致血管舒张。 它们也可能有助于解释偏头痛病理生理学中的一些关键事件，偏头痛的临床症状通常是由压力引起的。

Mast cells are known for their involvement in allergic reactions where they secrete many vasoactive and proinflammatory molecules. Mast cells are located perivascularly close to nerve endings and are activated by nerve stimulation. Acute psychological stress by immobilization triggered dura mast cell degranulation and resulted in cerebrospinal fluid (CSF) increase of rat mast cell protease (RMCP) I. These effects were inhibited by pretreatment with neutralizing antiserum for corticotropin-releasing hormone (CRH), treatment with the CRH-receptor antagonist Antalarmin or treatment neonatally with capsaicin to deplete sensory nerve fibers of their substance P (SP) content. Intradermal administration of CRH, and its structural analog urocortin, degranulated skin mast cells and increased vascular permeability; this process was dependent on mast cells and was mediated by specific CRH receptors. We are hypothesizing that CRH released outside the blood-brain barrier (BBB), directly or through SP, leads to dura mast cell degranulation and release of vasodilatory molecules, such as histamine. This action could help explain the pathophysiology of migraines and could serve as a possible model for the screening of relevant drugs. We will test this premise by investigating: (a) the effect of CRH and urocortin on dura mast cell degranulation and vasodilation by measuring Evans blue of 125I-BSA extravasation in the dura of C57 BL/6J mice; vasodilation will also be ascertained with the use of a fiberoptic probe designed to detect temporal blood flow, blood volume and oxygenation, while jugular venous samples will be assayed for histamine and methylistamine; (b) the effect of immobilization stress on dura mast cell degranulation and dura vasodilation with or without pretreatment with the CRH receptor antagonist Astressin or the nonpeptide NK1-receptor antagonist SR 140.333; (c) dura vasodilation as in (a-b) in W/Wv mast cell deficient mice to determine the need for mast cells, in CRH knock-out mice to examine the role of CRH, as well as in SP and NK1-receptor knock-out mice to investigate the need for SP. These studies will help us understand how certain neuropeptides released under stress trigger dura mast cell secretion leading to vasodilation. They may also help explain some key events in the pathophysiology of migraines, the clinical symptoms of which are often precipitated by stress.