STIMULUS-RESPONSE COUPLING IN PLATELETS

该项目旨在了解代谢的作用， 花生四烯酸磷脂在血小板刺激-反应偶联中的作用。 “磷脂酰肌醇效应”的中间体和终产物， 磷脂酶A2和C，以及环氧合酶和脂氧合酶将被 测定了 理由是，解决这一问题的主要障碍是： 磷脂代谢/花生四烯酸的因果关系 血小板对刺激的反应中的氧合部分是因为 这些过程通常是在血小板对 最强的激动剂 因此，大部分新陈代谢可能是一种 血小板完全活化的结果，而不是表达 调节或第二信使作用。 此外，很可能 不同的途径（例如磷脂酶A2与磷脂酶C）将发挥作用 不同的监管要求。 这将通过比较来分析 对弱激动剂和强激动剂的反应，对弱激动剂的反应， 允许或抑制聚集介导的活化的激动剂， 以及在各种代谢物存在下对激动剂的反应 抑制剂的 这应该允许不同途径的相关性， 特殊的生理功能。 花生四烯酸磷脂代谢将 然后用花生四烯酸、硬脂酸或 甘油和通过测量32 P掺入磷脂酸。 将通过薄层色谱法分离代谢产物，并进行高效液相色谱分析。 高效液相色谱法

This project is aimed at an understanding of the role of the metabolism of arachidonyl phospholipids in stimulus-response coupling in platelets. Intermediates and end products of the "phosphatidyl inositol effect", of phospholipases A2 and C, and of cyclooxygnase and lipoxygenase will be measured. The rationale is that the major barrior to resolution of the cause-effect relationships of phospholipid metabolism/arachidonate oxygenation in the response of platelets to stimuli is in part because these processes are usually measured during the platelet response to the strongest agonists. Much of the metabolism is thus likely to be a consequence of full platelet activation rather than an expression of a regulatory or second messenger role. Furthermore, it is likely that different pathways (e.g. phospholipase A2 vs phospholipase C) will function under different regulatory demands. This will be analyzed by comparing metabolism in response to weak vs strong agonists, in response to weak agonists where aggregation-mediated activation is permitted or inhibited, and in response to agonists in the presence of various metabolic inhibitors. This should permit correlation of different pathways with specific physiological functions. Arachidonyl phospholipid metabolism will be followed by pre-labelling phospholipids with arachidonate, stearate, or glycerol and by measuring incorporation of 32P into phosphatidic acid. Metabolities will be separated by thin-layer chromatography and high performance liquid chromatography.