Physiological and morphological responses of the rat kidney to reduced dietary protein.
Physiological and morphological responses of the rat kidney to reduced dietary protein.
复制标题
大鼠肾脏对膳食蛋白质减少的生理和形态反应。
DOI：
10.1152/ajprenal.1985.248.1.f31
复制
发表时间：
1985
期刊：
影响因子：
--
通讯作者：
Crossley,B
中科院分区：
文献类型：
--
作者：
Schmidt-Nielsen,B;Barrett,JM;Graves,B;Crossley,B
在年轻的Munich-Wistar大鼠中研究了对减少蛋白质饮食的肾脏生理和形态调整。两组动物用于相关的生理-形态学研究：正常蛋白质（NP，24%膳食蛋白）大鼠和减少蛋白质（LP，8%膳食蛋白）大鼠。两组均喂饲各自的饲料4-5 wk，并自由饮用水。对每组5只动物进行GFR和尿素清除率的生理学测量。这些数据表明，肾功能的变化特别且几乎完全影响尿素的处理。NP和LP大鼠之间的GFR无差异。LP大鼠的尿素清除率显著降低。对每组5只动物的灌注固定肾脏进行形态学分析。通过光学显微镜和电子显微镜检查并拍摄所选切片。这些数据表明，在大小和数量的元素内的维管束没有差异，但显示显着更小的管腔的薄肢的短循环肾单位和显着变薄的壁的薄降肢的长循环肾单位。这些形态学变化可能是部分负责观察到的生理调整，以减少蛋白质饮食。对另外一组大鼠（6只NP和5只LP，均脱水）分析溶质在内髓内的分布。数据显示，尿素的浓度，但不是Na+的浓度，在LP大鼠的乳头尖端减少。
Renal physiological and morphological adjustments to a reduced protein diet were studied in young Munich-Wistar rats. Two groups of animals were used for the correlative physiological-morphological studies: normal protein (NP, 24% dietary protein) rats and reduced protein (LP, 8% dietary protein) rats. Both groups were fed their respective diets for 4-5 wk and had free access to drinking water. Physiological measurements of GFR and urea clearance were made on five animals from each group. These data showed that the changes in renal function specifically and almost exclusively affected the handling of urea. There was no difference in GFR between the NP and LP rats. Urea clearance was substantially reduced in LP rats. Morphological analyses were made on perfusion-fixed kidneys of five animals from each group. Selected slices were examined and photographed by light and electron microscopy. These data showed no difference in size and number of elements within the vascular bundles but showed significantly smaller lumina of the thin limbs of the short-looped nephrons and a significant thinning of the wall of the thin descending limbs of the long-looped nephrons. These morphological changes may in part be responsible for the observed physiological adjustments to a reduced protein diet. An additional group of rats (6 NP and 5 LP, all dehydrated) were analyzed for distribution of solutes within the inner medulla. The data showed that the concentration of urea, but not that of Na+, was reduced at the papillary tip in LP rats.