Stored renin isoforms in the developing rat kidney.
Stored renin isoforms in the developing rat kidney.
复制标题
发育中的大鼠肾脏中储存的肾素同工型。
DOI：
10.1016/s0895-7061(97)00417-2
复制
发表时间：
1998
影响因子：
3.2
通讯作者：
Ingelfinger,JR
中科院分区：
文献类型：
--
作者：
Norling,LL;Smith,TM;Ingelfinger,JR
胎鼠肾脏的肾脏微血管中含有肾素，而成年大鼠肾脏的肾小球细胞中主要含有肾素。据推测，这些肾组织中储存的肾素亚型可能在化学和功能上有所不同。为了验证这一假设，通过用胃蛋白酶抑制剂琼脂糖从成人和胎儿肾匀浆中分离出肾素，比较了胎儿和成年大鼠肾中储存的肾素亚型。用一维聚丙烯酰胺凝胶电泳（SDS-PAGE）通过相对分子大小或用二维（2D）凝胶电泳通过等电点（pI）和大小分离胃蛋白酶抑制剂洗脱的肾素亚型。通过银染色或免疫印迹鉴定亚型。胃蛋白酶抑制剂处理的肾匀浆的一维聚丙烯酰胺凝胶电泳显示在约45 kDa范围内的银染条带，其对应于在2D凝胶上始终观察到的银染斑点。在胎儿肾匀浆中，1045 kDa条带的pI为5.3 ± 0.1，而成人样品中相应条带的基础pI为6.0 ± 0.05。测量血管紧张素I的生成以评估肾素酶活性。胎肾组织匀浆中无活性的肾素明显高于成人（60.2 ± 22.4v9.6 ± 4.0ng AI/mg蛋白/h，P<0.05）。胎肾组织匀浆中活性肾素含量显著低于成人（5.4 ± 0.4v36.5 ± 14.2ng AI/mg蛋白/h，P<0.05）。胎肾组织匀浆中总肾素活性显著高于成人组织匀浆（65.6 ± 22.3v46.0 ± 15.2，P <0.05）。这些结果表明，在胎儿和成人肾脏中发现的储存的肾素的物理和酶的形式的主要差异。据推测，这些变化中存储的肾素异构体发挥了作用，在肾内的肾素血管紧张素系统的发展差异调节。
Fetal rat kidney contains renin in renal microvasculature, whereas adult rat kidney contains renin predominantly in juxtaglomerular cells. It is hypothesized that renin isoforms stored within these renal tissues may differ chemically and functionally. To test this hypothesis, stored renin isoforms in fetal and adult rat kidney were compared by isolating renin from adult and fetal kidney homogenate with pepstatin agarose. Pepstatin-eluted renin isoforms were separated by relative molecular size using one-dimensional polyacrylamide gel electrophoresis (SDS-PAGE), or by isoelectric point (pI) and size using two-dimensional (2D) gel electrophoresis. Isoforms were identified either by silver staining or immunoblotting. One-dimensional polyacrylamide gel electrophoresis of pepstatin-treated kidney homogenates showed a silver-stained band in the range of ∼45 kDa, which corresponded to a silver-stained spot consistently seen on 2D gels. In fetal kidney homogenate, the ∼45 kDa band had a pI of 5.3 ± 0.1, whereas the corresponding band in adult samples had a basic pI of 6.0 ± 0.05. Angiotensin I generation was measured to assess renin enzymatic activity. There was significantly more inactive renin in fetal kidney homogenate than in adult kidney homogenate (60.2 ± 22.4v9.6 ± 4.0 ng AI/mg protein/h,P< .05). There was significantly less active renin in fetal kidney homogenate than in adult kidney homogenate (5.4 ± 0.4v36.5 ± 14.2 ng AI/mg protein/h,P< .05). The average total renin activity in fetal kidney homogenate was significantly higher than in adult kidney homogenate (65.6 ± 22.3v46.0 ± 15.2,P< .05). These results demonstrate major differences in the physical and enzymatic forms of stored renin found in fetal and adult kidney. It is speculated that these variations in stored renin isoforms play a role in the developmental differential regulation of the intrarenal renin angiotensin system.