Bradykinin B2 receptor antagonist increases chloride and water absorption in rat medullary collecting duct.
Bradykinin B2 receptor antagonist increases chloride and water absorption in rat medullary collecting duct.
复制标题
缓激肽 B2 受体拮抗剂可增加大鼠髓质集合管中氯离子和水的吸收。
DOI：
10.1152/ajpregu.1996.271.2.r352
复制
发表时间：
1996
期刊：
影响因子：
--
通讯作者：
Ploth,DW
中科院分区：
文献类型：
--
作者：
Mukai,H;Fitzgibbon,WR;Bozeman,G;Margolius,HS;Ploth,DW
本研究验证了肾内激肽通过改变集合管对氯的吸收而对电解质排泄起调节作用的假说。我们测定了Dahl/Rapp耐盐(SR/JR)大鼠延髓集合管(MCD)经Bellini管微导管插管后，经缓激肽受体拮抗剂HOE-140治疗前后肾小管液中氯离子和胰岛素的浓度。分别从左肾髓内末端(t-IMCD)和髓外末端(OMCD)收集管腔积液。HOE-140(n=7)或赋形剂(n=5)静脉滴注，重复采集。HOE-140不改变肾小球滤过率，但降低尿流率(P<；0.05)和绝对及部分氯离子排泄量(P<；0.01)。HOE-140不改变向OMCD传递过滤的氯离子(FDCl)的比例，但将FDCl向t-IMCD的比例从2.3+/-0.3降至1.3+/-0.3%(P<；0.05)。两个采集点之间每毫米吸收的过滤氯离子比例从0.2+/-0.1增加到0.6+/-0.1%(P<；0.05)。沿MCD方向的吸水率也增加(P<；0.05)。赋形剂处理组大鼠的排泄功能、肾小管吸氯率和吸水率均无明显变化。这些研究表明，激动素B2受体阻断增强了MCD对氯离子和水的吸收，这一发现支持了肾激肽在调节氯化钠和水排泄中的作用。
This study tested the hypothesis that intrarenal kinins play a regulatory role in electrolyte excretion by altering Cl- absorption in the collecting duct. We measured Cl- and insulin concentrations in tubular fluid samples obtained from medullary collecting ducts (MCD) of Dahl/Rapp salt-resistant (SR/ Jr) rats by microcatheterization of ducts of Bellini before and after treatment with the bradykinin receptor antagonist HOE-140. Tubular fluid was obtained from paired terminal inner medullary (t-IMCD) and outer medullary (OMCD) collecting duct sites of the left kidney. HOE-140 (n = 7) or vehicle (n = 5) was infused intravenously, and the collections were repeated. HOE-140 did not alter glomerular filtration rate but decreased urine flow rate (P < 0.05) and absolute and fractional Cl- excretion (P < 0.01). HOE-140 did not alter the fraction of filtered Cl- delivered (FDCl) to the OMCD but decreased FDCl to the t-IMCD from 2.3 +/- 0.3 to 1.3 +/- 0.3% (P < 0.05). The fraction of filtered Cl- absorbed per millimeter between the collection sites was increased from 0.2 +/- 0.1 to 0.6 +/- 0.1% (P < 0.05). Fractional absorption of water along the MCD was also increased (P < 0.05). No changes in excretory function or tubular Cl- or water absorption were observed in vehicle-treated rats. These studies show that kinin B2 receptor blockade enhances Cl- and water absorption in the MCD, a finding that supports a role of renal kinins in the regulation of NaCl and water excretion.