Interleukin and the Magnocellular Neuroendocrine System

描述（由申请人提供）：神经内分泌系统对感染和炎症期间外周释放的细胞因子作出反应。然而，新出现的证据表明，在中枢神经系统内存在表达白细胞介素-1 β（IL-1 β）的内在神经系统。在大细胞神经内分泌系统中，IL-1 β包含在分泌颗粒中，与催产素（OT）和加压素（VP）分开，指示独立释放。这种细胞因子可以调节神经垂体激素的分泌，在慢性刺激期间，通过饮用高渗盐水（2%氯化钠）和哺乳，因为所有三种肽都从神经叶耗尽。拟议的研究重点是了解IL-1 β在大细胞系统中的神经生物学，以及它与肾上腺素和一氧化氮（NO）在调节OT从大细胞神经元的细胞体和树突及其轴突终末在神经叶中的释放中的相互作用。采用免疫亲和毛细管电泳-激光诱导荧光检测法，对饮用2%NaCl 1、3、5和8天并复水的动物，以及哺乳2、5、10、10天的大鼠，血浆中IL-1 β、OT和VP及其在视上核（SON）和神经叶中含量的定量关系进行了表征。15和21天，断奶。SON区域的相同微透析液样品中的IL-1 β、OT和VP也将通过免疫毛细管电泳和激光间接荧光检测进行定量，以检查a）局部输注的IL-1 β是否改变OT从大细胞神经元的树突释放; B）在饮用2%NaCl的1、3、5或8天期间，SON区域内发生IL-1 β的内源性释放;和c）SON区域中响应于饮用2%NaCl的OT和IL-1 β释放被IL-1受体拮抗剂、前列腺素合成抑制剂（甲氨蝶呤）和一氧化氮合酶（L-NAME）或神经元传导阻断剂（河豚毒素、ω-芋螺毒素GVIA和ω-蛇毒素IVA）改变。最后，我们将功能地图（Fos表达;免疫组织化学）前脑区（穹窿下器官SFO;血管器终板，OVLT;正中视前核），激活大细胞系统后饮用2%氯化钠2或8天，并确定如果脑室内给药的IL-1受体拮抗剂改变这种反应。拟议的研究将提供大细胞系统中IL-1 β的功能评估及其对慢性刺激期间大细胞神经内分泌系统中OT（和VP）的中枢（核内）和外周释放的神经调节作用。

DESCRIPTION (provided by applicant): Neuroendocrine systems respond to cytokines released peripherally during infection and inflammation. Emerging evidence, however, reveals that within the central nervous system there are intrinsic neural systems expressing interleukin-1beta (IL-1beta). In the magnocellular neuroendocrine system, IL-1beta is contained in secretory granules separate from oxytocin (OT) and vasopressin (VP) indicative of independent release. This cytokine may modulate secretion of neurohypophysial hormones during chronic stimulation by drinking hypertonic salt water (2 percent NaCI) and by lactation, as all three peptides become depleted from the neural lobe. The proposed research is focused on understanding the neurobiology of IL-1beta in the magnocellular system and its interaction with prostaglandins and nitric oxide (NO) in the regulation of OT release from the cell bodies and dendrites of magnocellular neurons and from their axon terminals in the neural lobe. Using immunoaffinity capillary electrophoresis with laser-induced fluorescence detection, the quantitative relation-ships among IL-1beta, OT and VP in plasma and their content in the supraoptic nucleus (SON) and neural lobe will be characterized from animals that drink 2 percent NaCI for 1, 3, 5 and 8 days and are rehydrated, as well as from rats that are lactating for 2, 5, 10, 15 and 21 days and are weaned. IL-1beta, OT and VP in the same microdialysate samples of the SON area will also be quantified by immunocapillary electrophoresis with laser-indirect fluorescence detection to examine whether a) IL-1beta infused locally alters dendritic release of OT from magnocellular neurons; b) endogenous release of IL-1beta occurs within the SON area during 1, 3, 5 or 8 days of drinking 2 percent NaCI; and c) OT and IL-1beta release in the SON area in response to drinking 2 percent NaCI is altered by an IL-1 receptor antagonist, inhibitors of prostaglandin synthesis (meclofenamate) and nitric oxide synthase (L-NAME) or by blockers of neuronal conduction (tetrodotoxin, omega conotoxin GVIA and omega-agatoxin IVA). Lastly, we will functionally map (Fos expression; immunohistochemistry) forebrain areas (subfornical organ SFO; organum vasculosum lamina terminalis, OVLT; median preoptic nucleus) that activate the magnocellular system after drinking 2 percent NaCI for 2 or 8 days and determine if intracerebroventricular administration of an IL-1 receptor antagonist alters this response. The proposed research will provide a functional assessment of IL-1beta in the magnocellular system and its neuromodulatory role on the central (intranuclear) and peripheral release of OT (and VP) from the magnocellular neuroendocrine system during chronic stimulation.