Barrett J D, Eggena P
Veterans Administration Medical Center, Sepulveda, CA 91343.
Can J Physiol Pharmacol. 1991 Sep;69(9):1315-20. doi: 10.1139/y91-194.
Divergent conclusions exist as to whether inactive renin is present in nephrectomized rat plasma. A major factor contributing to this conflict may be related to significant changes in the "plasma blank" when trypsin-treated plasma is subjected to angiotensin I (AI) radioimmunoassay (RIA). In normal, but not nephrectomized rat plasma, AI-like substances are present in direct proportion to active renin. These substances are destroyed by trypsin. However, trypsin generates additional AI-like material, in both normal and nephrectomized rat plasma. This material, which is present in proportion to the renin substrate concentration, does not appear to be tetradecapeptide (TDP). In normal plasma, however, exogenous TDP is converted to AI in proportion to the active renin concentration and AI generation from TDP is increased by activation of inactive renin. However, in nephrectomized rat plasma, no AI generation from TDP was evident either before or after trypsin treatment. The coincident tryptic generation of a substance that quenches the levels of AI detected by RIA, combined with significant changes in the levels of endogenous and trypsin generated AI-like substances, may have significant bearing on the measured levels of inactive renin.
关于肾切除大鼠血浆中是否存在无活性肾素，存在不同的结论。导致这种矛盾的一个主要因素可能与胰蛋白酶处理后的血浆进行血管紧张素I（AI）放射免疫测定（RIA）时“血浆空白”的显著变化有关。在正常但非肾切除大鼠的血浆中，类AI物质与活性肾素成正比。这些物质会被胰蛋白酶破坏。然而，胰蛋白酶在正常和肾切除大鼠的血浆中都会产生额外的类AI物质。这种与肾素底物浓度成正比的物质似乎不是十四肽（TDP）。然而，在正常血浆中，外源性TDP会根据活性肾素浓度转化为AI，并且无活性肾素的激活会增加TDP生成AI的量。然而，在肾切除大鼠的血浆中，无论是在胰蛋白酶处理之前还是之后，都没有明显的TDP生成AI的现象。胰蛋白酶同时产生一种能淬灭RIA检测到的AI水平的物质，再加上内源性和胰蛋白酶产生的类AI物质水平的显著变化，可能对无活性肾素的测量水平有重大影响。
