Karet F E, Davenport A P
Clinical Pharmacology Unit, University of Cambridge, England.
J Cardiovasc Pharmacol. 1995;26 Suppl 3:S268-71.
By virtue of its exquisite sensitivity to the effects of endothelin-1 (ET-1), the kidney has been a consistent candidate for a pathophysiologic role for the endothelins. However, observed species differences in both receptor distribution and the subtypes mediating vasoconstriction have necessitated the development of a novel quantitative RT-PCR assay suitable for the direct investigation of human tissue, which is usually available only in very small amounts (i.e., biopsy specimens). In this study we quantified ETA and ETB receptor mRNA in normal renal cortex and medulla. For seven samples, cortex contained 0.19 +/- 0.10 amol ETA mRNA and 1.09 +/- 0.38 amol ETB mRNA/microgram total RNA (mean +/- SEM). In medulla these values were 0.47 +/- 0.25 and 2.17 +/- 1.90, respectively. The ratios of ETA to ETB were about 20:80, which correlates closely with previous studies of expressed receptor protein. This fluorescent nested quantitative RT-PCR assay provides a tool for further investigation of the human ET system at the molecular level in tissue from living individuals, and is of general applicability to the study of endogenous ligand-receptor systems.
由于肾脏对内皮素 -1（ET -1）的作用具有极高的敏感性，它一直被认为是内皮素发挥病理生理作用的一个重要器官。然而，由于观察到不同物种在内皮素受体分布以及介导血管收缩的亚型上存在差异，因此需要开发一种适用于直接检测人类组织的新型定量逆转录聚合酶链反应（RT -PCR）检测方法，因为人类组织通常数量极少（如活检标本）。在本研究中，我们对正常肾皮质和髓质中的ETA和ETB受体mRNA进行了定量分析。对于七个样本，皮质中每微克总RNA含有0.19±0.10 amol的ETA mRNA和1.09±0.38 amol的ETB mRNA（平均值±标准误）。在髓质中，这些值分别为0.47±0.25和2.17±1.90。ETA与ETB的比例约为20:80，这与之前关于表达的受体蛋白的研究结果密切相关。这种荧光嵌套定量RT -PCR检测方法为在活体个体组织的分子水平上进一步研究人类ET系统提供了一种工具，并且普遍适用于内源性配体 -受体系统的研究。
