Medullary injury in the ageing rat kidney: functional-morphometric correlations.
Medullary injury in the ageing rat kidney: functional-morphometric correlations.
复制标题
衰老大鼠肾脏的髓质损伤：功能-形态相关性。
DOI：
10.1046/j.1365-2362.1997.1140651.x
复制
发表时间：
1997
影响因子：
5.5
通讯作者：
Rosen,S
中科院分区：
文献类型：
--
作者：
Greenfeld,Z;Stillman,IE;Brezis,M;Rosen,S
人类和动物的尿液浓缩能力都随着年龄的增长而下降。这一现象尚不清楚地解释或证实的形态学结果，通常集中在肾小球的变化。在5-22月龄的大鼠中，进行半定量和定量的形态计量学分析，以评分皮质和髓质的变化。形态指标与肾功能参数相关。肾小管间质损伤可分为三个阶段：轻度纤维化伴肾小管间质损伤(I期)；轻度纤维化伴髓质厚升支萎缩和管型形成(期II)；广泛纤维化和萎缩伴大管型形成(期III)。尿最大渗透压与肾小管间质损伤分期呈正相关(r= −0.8，P<； 0.0001)，肾小管间质损伤与肾小球硬化的进展速度随年龄的增长呈解离，由I期的3 735 −1降至II期的2 80 7和III期的1 567。肾小管间质损伤I期和II期仅2-3%的肾小球硬化，而粗大的上肢肾小管损伤显著增加，从I期的2%增加到II期的11%(P<； 0.002)。在III期，同时出现广泛的肾小球硬化(53%)和肾小管损伤(32%)。单肾切除加速了形态损伤和功能损害。我们的结论是，在肾脏老化的早期阶段，髓小管的损伤可能比肾小球的损伤更普遍，这可能是集中能力下降的原因。
Urinary concentrating ability decreases with age in both humans and animals. This phenomenon is not yet clearly explained or corroborated by morphological findings, often focused on glomerular changes. In rats aged 5–22 months, semi‐quantitative and quantitative morphometric analysis was performed to score cortical and medullary changes. Morphological data were related to renal functional parameters. Three stages of tubulointerstitial injury were observed: minimal findings (stage I); mild fibrosis with atrophy and casts in medullary thick ascending limbs (stage II); extensive fibrosis and atrophy with large cast formation (stage III). Maximal urinary osmolality decreased in correlation with the stage of tubulointerstitial injury (r= −0.8,P< 0.0001), from 3735 mosmol L−1at stage I to 2807 at stage II and 1567 at stage III. A dissociation was observed in the rate of progression with age between tubulointerstitial injury and glomerular sclerosis. Whereas sclerosis was observed in only 2–3% of glomeruli at both stages I and II of tubulointerstitial injury, damage to thick ascending limbs significantly increased from 2% of tubules at stage I to 11% at stage II (P< 0.002). At stage III, both extensive glomerular sclerosis (53%) and tubular injury (32%) were present. Uninephrectomy accelerated both morphological injury and functional compromise. We conclude that, in the early stages of renal ageing, injury to medullary tubules may be more prevalent than injury to glomeruli and could be responsible for the reduction in concentrating ability.