Effect of dopamine on the tubuloglomerular feedback mechanism.
Effect of dopamine on the tubuloglomerular feedback mechanism.
复制标题
多巴胺对肾小球反馈机制的影响。
DOI：
10.1152/ajprenal.1990.258.4.f790
复制
发表时间：
1990
期刊：
影响因子：
--
通讯作者：
Briggs,JP
中科院分区：
文献类型：
--
作者：
Schnermann,J;Todd,KM;Briggs,JP
在麻醉大鼠中进行实验，以检查多巴胺的输注是否与肾小管肾小球反馈（TGF）反应的停止流压（PSF）和早期近端流速（VEP）的减少有关，以增加Henle流环。这些研究的目的是进一步测试肾血管舒张是TGF反应性降低的非特异性原因这一提议的有效性。当用肾上腺主动脉夹保持股动脉压恒定时，以4、15、35和75 μ g·kg-1·min-1的速率静脉输注多巴胺可诱导肾血管阻力降低10.9、23.4、31.3和30.1%。最大PSF和VEP反应显着降低在所有剂量水平的多巴胺，而V1/2，产生半最大反应所需的流速，没有改变。在开始多巴胺输注后不到10分钟内发生TGF钝化。在10（-4）M时，管周注射多巴胺可使最大PSF反应从8.8 +/- 0.7降至4.6 +/- 0.53 mmHg（P <0.01），在10（-3）M时，从6.0 +/- 1.19降至3.6 +/- 0.55 mmHg（P <0.05）。结果是一致的概念，肾血管舒张可能会修改TGF的反应，通过防止充分的血管收缩反应，管腔NaCl浓度的变化。
Experiments were performed in anesthetized rats to examine whether infusion of dopamine is associated with a reduction in the tubuloglomerular feedback (TGF) response of stop-flow pressure (PSF) and early proximal flow rate (VEP) to increases of loop of Henle flow. The purpose of these studies was to test further the validity of the proposal that renal vasodilation is a nonspecific cause for diminished TGF responsiveness. When femoral arterial pressure was kept constant with a suprarenal aortic clamp, intravenous infusion of dopamine at rates of 4, 15, 35, and 75 micrograms.kg-1.min-1 induced a 10.9, 23.4, 31.3, and 30.1% decrease in renal vascular resistance. Maximum PSF and VEP responses were significantly reduced at all dose levels of dopamine, whereas V1/2, the flow rate required to produce the half-maximum response, was not altered. TGF blunting occurred within less than 10 min after starting the dopamine infusion. Peritubular infusion of dopamine reduced maximum PSF responses from 8.8 +/- 0.7 to 4.6 +/- 0.53 mmHg at 10(-4) M (P less than 0.01) and from 6.0 +/- 1.19 to 3.6 +/- 0.55 mmHg at 10(-3) M (P less than 0.05). The results are consistent with the notion that renal vasodilatation may modify TGF responses by preventing the full vasoconstrictor response to changes in luminal NaCl concentration.