Weinstein S W, Szyjewicz J
Am J Physiol. 1976 Sep;231(3):822-31. doi: 10.1152/ajplegacy.1976.231.3.822.
Sodium, chloride, and inulin concentrations were measured in plasma collected from the terminal portions of long efferent vessels at the subcapsular surface of the rat kidney. Sodium concentration equaled and the concentrations of chloride and inulin were less than those in peripheral plasma. During benzolamide infusion, chloride concentration equaled while inulin concentration remained less than in peripheral plasma. In free-flow micropuncture samples collected randomly during control conditions, chloride concentration rose rapidly in the early proximal tubule and then remained elevated and constant throughout the remainder of the proximal tubule accessible to micropuncture. These experiments indicate that normally tubular reabsorbate low in chloride and inulin is added to the blood traversing the early postglomerular vessels before reaching the kidney surface. Bases on the analyses of proximal tubular fluid, this type of reabsorbate appears available only from the early proximal tubular segment. We conclude that a close functional relationship exists between the first segment of the proximal tubule and the early postglomerular blood supply characteristic of the superficial cortical nephron.
在大鼠肾脏被膜下表面长传出血管末端采集的血浆中，测量了钠、氯和菊粉的浓度。钠浓度相等，氯和菊粉的浓度低于外周血浆中的浓度。在注入苯磺酰胺期间，氯浓度相等，而菊粉浓度仍低于外周血浆。在对照条件下随机采集的自由流动微穿刺样本中，氯浓度在近端小管早期迅速升高，然后在微穿刺可及的近端小管其余部分保持升高且恒定。这些实验表明，正常情况下，低氯和低菊粉的肾小管重吸收液在到达肾脏表面之前就被添加到流经肾小球后早期血管的血液中。基于对近端小管液的分析，这种类型的重吸收液似乎仅来自近端小管的早期节段。我们得出结论，近端小管的第一节段与浅表皮质肾单位特征性的肾小球后早期血液供应之间存在密切的功能关系。
