Pritchard J B, Booz G, Kleinzeller A
Am J Physiol. 1978 May;234(5):F424-31. doi: 10.1152/ajprenal.1978.234.5.F424.
Isolated renal tubules and renal clearance techniques were used to characterize the renal handling of 2-deoxy-D-galactose (2-d-Gal) by the winter flounder (Pseudopleuronectes americanus). In vitro, energy-dependent, pH-sensitive uptake of 2-d-Gal (2-100 micron) was seen at the antiluminal face of the cell. Clearance measurements showed net secretion of 2-d-Gal in vivo. The mean clearance of 2-d-Gal in 18 fish was 0.98 +/- 0.16 ml/h while the glomerular filtration rate (GFR) was only 0.37 +/- 0.10 ml/h. Secretion was associated with marked renal accumulation of both 2-d-Gal and phosphorylated derivatives (2-d-Gal-1-phosphate). Tissue-to-plasma ratios (T/P) averaged 19 for free sugar and 59 for total sugar. Both clearance ratio and T/P were reduced to approximately 1 by injection of galactose (2.5 mmol/kg) simultaneously with 2-d-Gal (25 mumol/kg). Phlorizin (2.5 mumol/kg) increased net 2-d-Gal secretion, whereas glucose (2.5 mmol/kg) produced no change in secretion. Both compounds depressed 2-d-Gal T/P. This result suggests the presence of readsorptive transport at the brush border, sensitive to glucose and phlorizin.
利用分离的肾小管和肾清除技术，对美洲拟庸鲽（Pseudopleuronectes americanus）肾脏对2-脱氧-D-半乳糖（2-d-Gal）的处理进行了表征。在体外，在细胞的抗腔面观察到2-d-Gal（2-100微米）的能量依赖性、pH敏感摄取。清除率测量显示2-d-Gal在体内有净分泌。18条鱼中2-d-Gal的平均清除率为0.98±0.16毫升/小时，而肾小球滤过率（GFR）仅为0.37±0.10毫升/小时。分泌与2-d-Gal和磷酸化衍生物（2-d-Gal-1-磷酸）在肾脏中的显著积累有关。游离糖的组织与血浆比值（T/P）平均为19，总糖为59。同时注射半乳糖（2.5毫摩尔/千克）和2-d-Gal（25微摩尔/千克）后，清除率比值和T/P均降至约1。根皮苷（2.5微摩尔/千克）增加了2-d-Gal的净分泌，而葡萄糖（2.5毫摩尔/千克）对分泌无影响。两种化合物均降低了2-d-Gal的T/P。这一结果表明在刷状缘存在对葡萄糖和根皮苷敏感的重吸收转运。
