el-Dahr S S, Gomez R A, Gray M S, Peach M J, Carey R M, Chevalier R L
Department of Pediatrics, University of Virginia, Charlottesville 22908.
Am J Physiol. 1990 Apr;258(4 Pt 2):F854-62. doi: 10.1152/ajprenal.1990.258.4.F854.
Angiotensin II is an important mediator of renal vasoconstriction resulting from chronic unilateral ureteral obstruction (UUO). Distribution of renin mRNA and immunoreactive renin (IR) was examined in kidneys of 1-mo-old Sprague-Dawley rats subjected to either sham operation (n = 21), left complete UUO (n = 21), or right uninephrectomy (UNX, n = 16) at 2 days of age. There were no differences among the three groups in mean arterial pressure or plasma renin activity. Unlike sham kidneys, in which IR was detected in less than 55% of juxtaglomerular apparatuses (JGA) and was confined to a juxtaglomerular location, IR in both kidneys of animals with UUO appeared in greater than 75% of JGA and extended along most of the length of the afferent arteriole (P less than 0.01). In contrast, IR in kidneys of UNX rats was localized to the JGA as in sham-operated animals. Compared with sham-operated kidneys, renal renin content was increased in the obstructed kidneys (P less than 0.01) but decreased in the intact opposite kidneys of UUO rats and in the remaining kidneys of UNX rats (P less than 0.05). Renin mRNA, detected by in situ hybridization histochemistry, was localized to the JGA in kidneys of all groups. However, the fraction of JGA containing detectable renin mRNA was higher in obstructed kidneys than in intact opposite, UNX, or sham kidneys (P less than 0.05). In conclusion, UUO alters intrarenal renin independent of the systemic renin-angiotensin system. The greater distribution of IR, increased renin content, and renin gene expression of kidneys with ipsilateral UUO are consistent with a role for renin-angiotensin in mediating the vasoconstriction resulting from UUO.
血管紧张素II是慢性单侧输尿管梗阻（UUO）所致肾血管收缩的重要介质。对1月龄的Sprague-Dawley大鼠在2日龄时进行假手术（n = 21）、左侧完全UUO（n = 21）或右侧单肾切除（UNX，n = 16），然后检测肾素mRNA和免疫反应性肾素（IR）在其肾脏中的分布。三组之间的平均动脉压或血浆肾素活性无差异。与假手术肾脏不同，假手术肾脏中不到55%的肾小球旁器（JGA）可检测到IR，且IR局限于肾小球旁位置，而UUO动物双侧肾脏中IR出现在超过75% 的JGA中，并沿入球小动脉的大部分长度延伸（P<0.01）。相比之下，UNX大鼠肾脏中的IR与假手术动物一样定位于JGA。与假手术肾脏相比，梗阻侧肾脏的肾素含量增加（P<0.01），但UUO大鼠对侧完整肾脏及UNX大鼠剩余肾脏中的肾素含量降低（P<0.05）。通过原位杂交组织化学检测到的肾素mRNA在所有组的肾脏中均定位于JGA。然而，含有可检测到的肾素mRNA的JGA比例在梗阻侧肾脏中高于对侧完整肾脏、UNX肾脏或假手术肾脏（P<0.05）。总之，UUO改变肾内肾素，与全身肾素-血管紧张素系统无关。同侧UUO肾脏中IR分布更广、肾素含量增加以及肾素基因表达增加，这与肾素-血管紧张素在介导UUO所致血管收缩中的作用一致。
