DeQuattro V, Sjoerdsma A
J Clin Invest. 1968 Oct;47(10):2359-73. doi: 10.1172/JCI105920.
Intravenous administration of tritium-labeled 3,4-dihydroxyphenylalanine (dopa) to human subjects resulted in the labeling of endogenous catecholamines and vanillylmandelic acid (VMA). Determination of the changes in specific activity of these compounds with time in fractional collections of urine and in cardiac biopsies from patients undergoing corrective cardiac surgery permitted estimation of apparent turnover rates. The average half-time of the exponential decline in specific activity of labeled urinary norepinephrine was about 8 hr and that of VMA was 11-16 hr in five normal subjects. No significant differences from normal were observed in eight patients with essential hypertension. The average half-life of norepinephrine was only 5 hr in cardiac patients undergoing surgery, and the levels and rate of decline of cardiac norepinephrine specific activity correlated well with the exponential phase of the urinary disappearance curve. There were significant effects of treatment with alpha-methyltyrosine, reserpine, and pargyline hydrochloride on the labeling and apparent turnover rates of norepinephrine and VMA; the effects noted were consistent with known actions of these three drugs. It is suggested that the technique used is a suitable means of assessing "over-all" catecholamine metabolism in man, particulary if combined with quantitative assay of urinary catecholamine metabolites.
给人体受试者静脉注射氚标记的3,4 - 二羟基苯丙氨酸（多巴），导致内源性儿茶酚胺和香草扁桃酸（VMA）被标记。通过对接受心脏矫正手术患者的尿液分段收集样本以及心脏活检样本中这些化合物的比活性随时间变化的测定，可以估算出表观周转率。在5名正常受试者中，标记的尿去甲肾上腺素比活性呈指数下降的平均半衰期约为8小时，VMA的平均半衰期为11 - 16小时。8名原发性高血压患者与正常情况无显著差异。接受手术的心脏病患者中去甲肾上腺素的平均半衰期仅为5小时，心脏去甲肾上腺素比活性的水平和下降速率与尿消失曲线的指数阶段密切相关。α - 甲基酪氨酸、利血平和盐酸优降宁治疗对去甲肾上腺素和VMA的标记及表观周转率有显著影响；观察到的这些影响与这三种药物的已知作用一致。有人提出，所使用的技术是评估人体“整体”儿茶酚胺代谢的一种合适方法，特别是如果与尿儿茶酚胺代谢物的定量测定相结合的话。
