ACTIONS AND INTERACTIONS OF UVEITIC MEDIATORS

治疗眼部炎症（葡萄膜炎）已被证明是一项艰巨的任务， 至少在一定程度上是由于参与的调解人众多， 了解其规则。 肿瘤坏死因子（TNF）和 白细胞介素-1（IL-1）是两种功能相关细胞因子， 眼外炎症反应和最近证实的炎性 影响眼睛。 我们认为TNF和IL-1是 葡萄膜炎通过它们经由两种不同的途径对葡萄膜组织的作用 机制：1）它们引起类二十烷酸（代谢物）的次级释放 花生四烯酸）和血小板活化因子（PAF）; 2）它们 直接与葡萄膜细胞相互作用，影响细胞水平的循环 核苷酸通过特异性结合到细胞表面-“G”蛋白连接 受体。 这一假设的第一部分将通过注射TNF 和IL-1进入兔眼的玻璃体腔并表征 它们在剂量反应、时间过程和细胞因子水平方面的作用 和互动。 类二十烷酸的贡献将通过确定 那些在尼古丁诱导的葡萄膜炎期间增加的，然后测量 环氧合酶（吲哚美辛，萘普生）和联合 环氧合酶/脂氧合酶（SK&F 86002）抑制剂，以改变细胞因子- 诱导效应。 将通过释放法测量房水提取物中的PAF 血小板中[~ 3 H]-5-羟色胺的释放及其在阿托品诱导的葡萄膜炎中的作用 通过测定特异性PAF受体拮抗剂的作用进行评估 (SRI 63-441）和玻璃体内注射的PAF的能力， PAF/类二十烷酸组合（在尼古丁诱导的细胞凋亡期间增加的那些） 葡萄膜炎），以再现组合的效果（增加 在尼古丁诱导的葡萄膜炎期间）以再现 玻璃体内注射的细胞因子。 在这个假设的第二部分， 细胞因子在体外诱导腺苷3 '，5'-环 通过虹膜、睫状体的单独制剂产生的cAMP 体和睫状突，以及影响 腺苷酸环化酶的活性，以改变精氨酸诱导的cAMP的产生，在 体外，将被测量。 这些试剂包括Gs蛋白激活剂（F-; 鸟苷5 '-[β，g-亚氨基]三磷酸），Gi抑制剂（百日咳 毒素）、蛋白激酶C（PKC）激活剂（4 β-佛波醇12-肉豆蔻酸酯13- 乙酸酯）和抑制剂（H7;星形孢菌素）和腺苷酸环化酶激活剂 （forskolin; Mn 2+）。 这些研究将提供宝贵的见解， TNF和IL-1调节次级代谢产物产生的机制 信使、cAMP和控制膜通透性的关键物质 和房水的产生。 重要的是， TNF和IL-1是次要介导这些作用的特定物质， 以及这些细胞因子对葡萄膜环核苷酸产生的影响 由于新的药理学模式即将问世， 可能用于治疗葡萄膜炎。

Treating ocular inflammation (uveitis) has proven a difficult task, due at least in part to the numerous mediators involved and an inadequate understanding of its regulation. Tumor necrosis factor (TNF) and interleukin-1 (IL-1) are two functionally related cytokines with potent inflammatory effects outside the eye and recently-demonstrated phlogistic effects in the eye. We suggest that TNF and IL-1 are key mediators of uveitis by virtue of their effects on uveal tissue via two distinct mechanisms: 1) They provoke secondary release of eicosanoids (metabolites of arachidonic acid) and platelet-activating factors (PAF); 2) They interact directly with uveal cells, affecting cellular levels of cyclic nucleotides through specific binding to cell surface-"G" protein-linked receptors. Part I of this hypothesis will be addressed by injecting TNF and IL-1 into the vitreal chamber of the rabbit eye and characterizing their effects in terms of dose-response, time course and cytokine levels and interactions. Eicosanoid contributions will be assessed by determining those that increase during cytokine-induced uveitis and then measuring the ability of cyclooxygenase (indomethacin, naproxen) and combined cyclooxygenase/lipoxygenase (SK&F 86002) inhibitors to alter cytokine- induced effects. PAF will be measured in aqueous humor extracts by release of [3H]-serotonin from platelets and its role in cytokine-induced uveitis assessed by determining the effect of a specific PAF receptor antagonist (SRI 63-441) and the ability of intravitreally-injected PAF and PAF/eicosanoid combinations (those which increase during cytokine-induced uveitis) to reproduce the effects of combinations (those which increase during cytokine-induced uveitis) to reproduce the effects of intravitreally-injected cytokines. In part II of this hypothesis the ability of cytokines, in vitro, to induce adenosine 3',5'-cyclic monophosphate (cAMP) production by individual preparations of iris, ciliary body and ciliary processes, and the ability of agents that influence adenylate cyclase activity to alter cytokine-induced cAMP production, in vitro, will be measured. These agents include Gs protein activators (F-; guanosine 5'-[beta, g-imino]triphosphate), a Gi inhibitor (pertussis toxin), protein kinase C (PKC) activators (4beta-phorbol 12-myristate 13- acetate) and inhibitors (H7; staurosporin) and adenylate cyclase activators (forskolin; Mn2+). These studies will provide valuable insight into the mechanisms by which TNF and IL-1 regulate production of the secondary messenger, cAMP, and pivotal substance controlling membrane permeability and aqueous humor production. It is important that the ocular effects of TNF and IL-1, the specific substances secondarily mediating these effects, and the influence of these cytokines on uveal cyclic nucleotide production be elucidated since new pharmacological modalities will soon be available for possible use in the treatment of uveitis.