Braun E J, Roy D R, Jamison R L
Am J Physiol. 1981 Dec;241(6):F612-7. doi: 10.1152/ajprenal.1981.241.6.F612.
A micropuncture study of Perognathus penicillatus, a small rodent native to the deserts of the southwestern United States was performed to evaluate the function of the superficial nephron. Data are reported for 12 animals of 17 g average body wt. Mean glomerular filtration rate was 475 +/- 73 microliter X min-1 X g kidney wt-1. Urine osmolality averaged 1,154 +/- 197 mosmol/kg H2O. Single nephron glomerular filtration rate averaged 43 nl X min-1 X g kidney wt-1 in the proximal tubule and 48 in the distal tubule, values that are not significantly different. In terms of the filtered load remaining unreabsorbed at the end of the accessible proximal tubule, the average percentages were 46 water, 48 total solute, 45 sodium, 56 phosphorus, 62 potassium, 71 magnesium, and 54 calcium. The concentrations of potassium and magnesium in fluid samples increased significantly along the proximal tubule. Approximately at the midpoint of the distal tubule, fractional delivery of water, 13.1%, was greater than that for total solute, 10%, or sodium, 7%, indicating that the intervening segment of nephron reabsorbed solute and sodium in excess of water. The function of the superficial nephron resembles that of species previously investigated except for potassium reabsorption in the proximal convoluted tubule.
对美国西南部沙漠地区的一种小型啮齿动物——刚毛更格卢鼠进行了微穿刺研究，以评估浅表肾单位的功能。报告了12只平均体重为17克的动物的数据。平均肾小球滤过率为475±73微升×分钟⁻¹×克肾重⁻¹。尿渗透压平均为1154±197毫摩尔/千克H₂O。近端小管的单肾单位肾小球滤过率平均为43纳升×分钟⁻¹×克肾重⁻¹，远端小管为48纳升×分钟⁻¹×克肾重⁻¹，二者数值无显著差异。就可及近端小管末端未被重吸收的滤过负荷而言，平均百分比分别为：水46%、总溶质48%、钠45%、磷56%、钾62%、镁71%、钙54%。近端小管中液体样本中的钾和镁浓度显著升高。在远端小管中点附近，水的分数排泄率为13.1%，高于总溶质的10%或钠的7%，这表明肾单位的中间段重吸收的溶质和钠超过了水。除了近端曲管中的钾重吸收外，浅表肾单位的功能与先前研究的物种相似。
