BIOCHEMICAL EVALUATION OF ADRENERGIC FUNCTION

去甲肾上腺素(NE)及其代谢物水平的测定 血浆、尿液和脑脊液中的前体 正在被开发并应用于研究这些变化 各种自主神经功能障碍患者体内的化合物 神经系统和给药后的大鼠 改变去甲肾上腺素的合成、储存、释放代谢或摄取 交感神经。药物，如地昔帕明(或可卡因)， 阻断摄取，增强去甲肾上腺素的表观释放 循环并减少其脱氨代谢物的形成， DHPG和MHPG。L-多巴是在交感中形成的 并溢出到血液中。这可能是一个重要的 神经元外多巴胺的来源和作为神经体液的作用 探员。直立性低血压患者有平行的 减少高香草酸(HVA)的排泄，这是主要的 多巴胺和去甲肾上腺素代谢物(MHPG 和VMA)。在动物和人类身上也存在类似的关系 去氢异喹对外周儿茶酚胺的抑制作用 新陈代谢。用MPTP处理的猴子来消灭 中枢多巴胺能神经元，我们已经建立了有效性 外推HVA与MHPG之间的回归线 测量脑组织HVA的生成量。这一点在两个国家都已经做到了 猴的尿液和血浆。一种快速酶促反应的方法 ~(18)F-多巴转化为~(18)F-多巴胺已取得进展。这个 18F-多巴胺将作为内源性药物的前体给予 ~(18)F-去甲肾上腺素的PET外周扫描研究 各种疾病状态下的交感神经元。

Measurement of levels of norepinephrine (NE), its metabolites, and precursors in plasma, urine, and cerebrospinal fluid have been developed and are being applied to studies of changes of these compounds in patients with various disorders of the autonomic nervous system and in rats after administration of drugs which alter synthesis, storage, release metabolism, or uptake of NE in sympathetic nerves. Drugs such as desipramine (or cocaine) which block uptake, enhance apparent release of norepinephrine into the circulation and diminish formation of its deaminated metabolites, DHPG and MHPG. L-DOPA is formed in the sympathetic neurones and overflows into the blood. It may be an important source of extraneuronal dopamine and act as a neurohumoral agent. Patients with orthostatic hypotension have parallel decreases in excretion of homovanillic acid (HVA), the major metabolite of dopamine, and norepinephrine metabolites (MHPG and VMA). A similar relationship holds in animals and humans treated with debrisoquin to inhibit peripheral catecholamine metabolism. Using monkeys treated with MPTP to destroy central dopaminergic neurones, we have established the validity of extrapolating the regression line relating HVA to MHPG to measure the brain HVA production. This has been done in both urine and plasma of monkeys. A means of rapid enzymatic conversion of 18F-dopa to 18F-dopamine has been developed. The 18F-dopamine is to be administered as a precursor of endogenous 18F-norepinephrine to study by PET scanning the peripheral sympathetic neurones in various disease states.