An examination of transcapillary water flux in renal inner medulla.
An examination of transcapillary water flux in renal inner medulla.
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肾内髓质经毛细血管水通量的检查。
DOI：
10.1152/ajplegacy.1976.231.2.313
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发表时间：
1976
期刊：
影响因子：
--
通讯作者：
R. Jamison
中科院分区：
文献类型：
--
作者：
V. Sanjana;P. Johnston;C. Robertson;R. Jamison
我们最近证实，液体净摄取发生在内髓的毛细血管系统中。为了确定液体摄取的部位，测定了Munich-Wister大鼠暴露的乳头底部和顶端直肠血管下行的血浆中蛋白质的浓度。直肠血管血浆/动脉血浆蛋白浓度比(VR/P)在底部为1.43+/-0.09，在顶端为1.66+/-0.09。这些结果表明直肠血管下行的液体丢失，仅凭液压和肿瘤力很难解释。直肠降血管内容物的渗透压在底部和顶端之间升高(增量=72+/-30momoL/kgH2O)。如果降支血管的血浆渗透压的增加滞后于邻近的髓质，则存在有利于降支血管失水的跨毛细血管渗透驱动力。结论：髓内循环的液体摄取发生在相互连接的直血管降支或直血管升支之外。在我们看来，对这些结果最有可能的解释是，液体通过内髓直血管的运动受到三种力的影响：由于跨毛细血管渗透压、肿胀压和液压的差异。
We recently demonstrated that net fluid uptake occurs in the capillary system of the inner medulla. To define the site of fluid uptake, the concentration of protein was determined in plasma from descending vasa recta at the base and tip of the exposed papilla in Munich-Wister rats. The vasa recta plasma-to-arterial plasma protein concentration ratio (VR/P) was 1.43 +/- 0.09 at the base and 1.66 +/- 0.09 at the tip. These results, which indicate fluid loss from the descending vasa recta, are difficult to explain on the basic of hydraulic and oncotic forces alone. The osmolality of the contents of descending vasa recta increased between base and tip (delta = 72 +/- 30 mosmol/kg H2O). If the increase in osmolality of plasma in descending vasa recta lags behind that of the adjacent medullary interstitium, a transcapillary osmotic driving force exists favoring water loss from descending vessels. It is concluded that fluid uptake by the inner medullary circulation occurs beyond descending vasa recta in interconnecting capillaries or ascending vasa recta. In our view the most likely interpretation of these results is that fluid movement across vasa recta in the inner medulla is influenced by three forces: those owing to transcapillary differences in osmotic, oncotic, and hydraulic pressures.