Development of renal function test using dopamine and its utility in laboratory

尿中排出的游离多巴胺来自肾小管多巴胺，它在近端小管合成，调节利钠和利尿。尿液中的游离多巴胺来源于血浆中的多巴胺，其数量可以忽略不计。我们研究了尿中游离多巴胺水平作为肾功能，尤其是肾小管活动的标志物的有用性。我们确定了尿中游离多巴胺水平与一些已建立的肾功能标志物之间的相关性。尿游离多巴胺水平与血肌酐、尿α_1、β_2微球蛋白水平呈负相关。受试者操作特征(ROC)分析表明，尿游离多巴胺水平在敏感性和特异性上优于其他已建立的肾脏参数。在肾脏疾病中，肾小管功能障碍患者的尿中游离多巴胺水平显著低于肾小球功能障碍患者。研究结果表明，尿中游离多巴胺水平是肾功能的一个指标，可用于评估肾脏损害，特别是肾小管功能障碍。

The free dopamine excreted in urine is derived from renal tubular dopamine, which is synthesized at the proximal tubules and regulates both natriuresis and diuresis. Urinary free dopamine derived from plasma dopamine is in negligible quantity. We investigated the usefulness of the urinary level of free dopamine as a marker of renal function, especially of tubular activity. We determined the correlations between the urinary level of free dopamine and a number of established markers of renal function. The urinary level of free dopamine was negatively correlated with the serum level of creatinine and the urinary levels of alpha_1-and beta_2-microglobulins. The receiver-operating characteristic (ROC) analysis indicated that urinary level of free dopamine is superior to other established renal parameters in sensitivity and specificity. In renal diseases, urinary level of free dopamine was significantly lower in patients with renal tubular dysfunction than in patients with glomerular dysfunction. Findings suggest that the urinary level of free dopamine is an index of renal function and is useful for evaluating renal impairments, especially renal tubular dysfunction.