Shikimi T, Suzuki S
Department of Pharmacology, Shimane Medical University, Japan.
Biol Chem Hoppe Seyler. 1990 Oct;371(10):991-7. doi: 10.1515/bchm3.1990.371.2.991.
Mouse kidney contains urinastatin (UT)-like immunoreactive substances with trypsin inhibitory activity. Immunohistochemical studies show that these UT-like substances are localized in the same region as kidney kallikrein, i.e. in the distal tubules. Sephadex column chromatography of mouse kidney extract using 0.1M NaCl as the eluent yielded fractions (C.F.) containing both UT-like and kallikrein-like material. In these fractions (C.F.), the removal of UT-like material caused a concomitant decrease in kallikrein-like activity and vice versa. However, when the kidney extract was eluted with an acidic buffer of high ionic strength, the fractions containing both UT-like and kallikrein-like substances were not observed. These results suggest that these two components are intimately bound to one another. The kallikrein activity responded differently to pH, to metal ions (zinc and copper), and to the sodium/potassium ratio, depending on the concomitant presence or absence of UT-like material. These findings suggest that kallikrein activity in kidney tissue is modified by the presence of an UT-like substance.
小鼠肾脏含有具有胰蛋白酶抑制活性的尿抑胃素（UT）样免疫反应性物质。免疫组织化学研究表明，这些UT样物质与肾激肽释放酶位于同一区域，即远曲小管。以0.1M NaCl作为洗脱剂对小鼠肾脏提取物进行葡聚糖凝胶柱层析，得到了含有UT样和激肽释放酶样物质的级分（C.F.）。在这些级分（C.F.）中，去除UT样物质会导致激肽释放酶样活性随之降低，反之亦然。然而，当用高离子强度的酸性缓冲液洗脱肾脏提取物时，未观察到同时含有UT样和激肽释放酶样物质的级分。这些结果表明这两种成分紧密结合在一起。取决于UT样物质的伴随存在或不存在，激肽释放酶活性对pH、金属离子（锌和铜）以及钠/钾比值的反应有所不同。这些发现表明肾脏组织中的激肽释放酶活性会因UT样物质的存在而发生改变。
