INVESTIGATION OF EXTRANEURONAL CATECHOL SYNTHESIZING ENZYMES IN THE CNS

我们以前对脑胶质瘤的免疫组化和生化研究表明， 微血管和脑血管内皮细胞培养显示 的苯乙醇胺-N-甲基转移酶（PNMT）的活动在这两个组织。 由于这些神经元组织含有一种合成 负责将去甲肾上腺素转化为 肾上腺素，我们扩展了这些研究，以确定是否血管PNMT 确实能够从去甲肾上腺素中产生肾上腺素 为此 目的直接测定内皮细胞分泌的肾上腺素， 采用高压液相色谱法测定去甲肾上腺素 层析 这些仍在进行中的研究表明， 培养的脑血管内皮细胞（第2 - 4代） 从分离的脑微血管部分（从大鼠获得）中， 能够将去甲肾上腺素转化为肾上腺素

Our previous immunohistochemical and biochemical studies of cerebral microvessels and cerebrovascular endothelial cultures showed the presence of phenylethanolamine-N-methyltransferase (PNMT) activity in both tissues. Since these extraneuronal tissues contain a catecholamine synthesizing enzyme which is responsible for conversion of norepinephrine to epinephrine, we extended these studies to determine whether vascular PNMT is indeed capable of producing epinephrine from norepinephrine. For this purpose a direct assay of endothelial epinephrine formed from norepinephrine was determined by using high pressure liquid chromatography. These studies, which are still in progress, have shown that the cultured cerebrovascular endothelium (2nd-4th generation) derived from dissociated cerebral microvascular fractions (obtained from rats) are capable of converting norepinephrine to epinephrine.