EVIDENCE FOR A PREGLOMERULAR OXYGEN DIFFUSION SHUNT IN RAT RENAL-CORTEX
EVIDENCE FOR A PREGLOMERULAR OXYGEN DIFFUSION SHUNT IN RAT RENAL-CORTEX
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DOI：
10.1152/ajprenal.1990.259.6.f910
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发表时间：
1990-12-01
影响因子：
--
通讯作者：
HECKMANN, U
中科院分区：
文献类型：
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作者：
SCHUREK, HJ;JOST, U;HECKMANN, U
尽管流向肾皮质的血流量高且吸氧量低，但肾皮质非常容易缺氧。由于促红细胞生成素的产生主要集中在肾皮质，因此本研究的目的是找到肾皮质内对缺氧和氧感应的高敏感性的共同点。通过使用微同轴针传感器直接测量麻醉的慕尼黑-威斯塔-弗洛姆特大鼠原位肾脏浅层肾小球的氧分压，我们获得了 46 +/- 13 (SD) mmHg (n = 71) 的平均 O2 (Po2) 分压值。同时测量的动脉血全身 Po2 为 90 +/- 8 mmHg (n = 54)。将呼吸器气体从空气改为纯氧后，全身动脉 Po2 增加至 593 +/- 27 mmHg，而浅层肾小球 Po2 仅增加至平均 80 +/- 28 mmHg (n = 71)。这些数据表明，皮质脉管系统内存在显着的肾小球前氧分流，最有可能在小叶间血管之间，这些血管以逆流方式排列，定量地代表肾皮质内动脉和静脉之间的最大接触面积。
Although blood flow to the renal cortex is high and oxygen extraction is low, the renal cortex is remarkably susceptible to hypoxia. Because erythropoietin production has been localized mainly to the renal cortex, the aim of this study was to find a common denominator for both the high susceptibility to hypoxia and oxygen sensing within the renal cortex. By direct measurement of oxygen pressure with microcoaxial needle sensors at superficial glomeruli of the in situ kidney of anesthetized Munich-Wistar-Fromter rats, we obtained mean partial pressure of O2(Po2) values of 46 +/- 13 (SD) mmHg (n = 71). The simultaneously measured systemic Po2 in arterial blood was 90 +/- 8 mmHg (n = 54). Changing the respirator gas from air to pure oxygen enhanced systemic arterial Po2 to 593 +/- 27 mmHg, whereas Po2 at the superficial glomeruli increased only to a mean of 80 +/- 28 mmHg (n = 71). These data suggest significant preglomerular shunting of oxygen within the cortical vasculature, most likely between interlobular vessels, which are arranged in a countercurrent fashion and represent quantitatively the largest contact area between arteries and veins within the renal cortex.