Gitlow S, Dziedzic S, Dziedzic L, Roubein I
Clin Exp Hypertens (1978). 1981;3(5):897-918. doi: 10.3109/10641968109033711.
Defective control of the cardiovascular system by the sympathetic nerves continues to be incriminated as the potential primary physiologic defect in essential hypertension (EH). The need to measure sympathetic tone has progressed from physiologic mensuration by assessment of reflex and pharmacological responses to the recent assay of norepinephrine (NE) and its congeners in both urine and plasma. The way in which the body handles D,L-B-3H-NE represents yet another technique by which to evaluate sympathetic function. Previous studies of EH by this method demonstrated more rapid plasma disappearance of 3H-NE as well as elevated 24 hour tritium accumulation in the urine following D,L-B-3H-NE injection. The present study of 7 normotensive subjects and 7 patients with EH was designed to depict more precisely these abnormalities in 3H-NE-metabolism. Following a one minute injection of 8 micrograms D,L-B-3H-NE, (200 microCi) intravenously, the excretion of unlabeled endogenous metabolites and their labeled congeners was assayed. By these means one could estimate catecholamine synthesis, turnover of the labeled pools, and by comparison of relative specific activities of the metabolites, gain some insight into the distribution of the injected material. Alternative catabolic pathways were evaluated by measurement of the excretion of 3H2O. Patients with EH excreted more label per 24 hours, revealed a more rapid decline of 3H2O excretion and lower specific activity of normetanephrine (NM). These findings are compatible with changes in pool dynamics and distribution of administered label which gave additional support to the concept of adrenergic dysfunction in association with essential hypertension.
交感神经对心血管系统控制的缺陷仍然被认为是原发性高血压（EH）潜在的主要生理缺陷。测量交感神经张力的需求已经从通过评估反射和药理反应的生理测定发展到最近对尿液和血浆中去甲肾上腺素（NE）及其同系物的测定。身体处理D，L-β-3H-NE的方式代表了另一种评估交感神经功能的技术。以前用这种方法对EH的研究表明，注射D，L-β-3H-NE后，血浆中3H-NE的消失更快，并且尿液中24小时氚的积累增加。本研究对7名血压正常的受试者和7名EH患者进行，旨在更精确地描述3H-NE代谢中的这些异常情况。静脉内注射8微克D，L-β-3H-NE（200微居里）1分钟后，测定未标记的内源性代谢物及其标记同系物的排泄情况。通过这些方法，可以估计儿茶酚胺的合成、标记池的周转率，并通过比较代谢物的相对比活性，对注射物质的分布有一些了解。通过测量3H2O的排泄来评估替代分解代谢途径。EH患者每24小时排泄的标记物更多，3H2O排泄下降更快，去甲变肾上腺素（NM）的比活性更低。这些发现与池动力学和给药标记物分布的变化相一致，这为与原发性高血压相关的肾上腺素能功能障碍的概念提供了额外的支持。
