Briggs J P, Levitt M F, Abramson R G
Am J Physiol. 1977 Nov;233(5):F373-81. doi: 10.1152/ajprenal.1977.233.5.F373.
Free-flow micropuncture and clearance studies were performed to evaluate the transport of allantoin inthe rat kidney. Inn all studies [2-14C]uric acid and [methoxy-3H]inulin were administered. With a two-step column chromatographic technique, radiolabeled uric acid and allantoin were separated in plasma, urine, and tubular fluid, and the [2-14C]allantoin concentration was determined. Tubular fluid collections were obtained under hydropenic and control coneated animals in the control and volume-expanded states. Clearance data were obtained in oxonic acid-treated animals under the same experimental conditions. These studies indicate that allantoin is not bound to plasma protein and is, therefore, freely filterable. Neither net reabsorption nor net secretion of allantoin was evident along the length of the nephron. The bubular handling of allantoin was demonstrated to be dissociated from that of uric acid in all experimental states. No significant intrarenal production of allantoin from uric acid was observed.
进行了自由流动微穿刺和清除率研究，以评估大鼠肾脏中尿囊素的转运情况。在所有研究中，均给予了[2-¹⁴C]尿酸和[甲氧基-³H]菊粉。采用两步柱色谱技术，在血浆、尿液和肾小管液中分离出放射性标记的尿酸和尿囊素，并测定了[2-¹⁴C]尿囊素的浓度。在禁水和对照的浓缩动物处于对照和容量扩张状态下收集肾小管液。在相同实验条件下，在服用氧嗪酸的动物中获得清除率数据。这些研究表明，尿囊素不与血浆蛋白结合，因此可自由滤过。沿肾单位全长均未发现尿囊素的净重吸收或净分泌。在所有实验状态下，均证明尿囊素的肾小管处理与尿酸的不同。未观察到肾脏内由尿酸产生尿囊素的显著情况。
