Gaudio K M, Thulin G, Ardito T, Kashgarian M, Siegel N J
Department of Pediatrics and Pathology, Yale University School of Medicine, New Haven, Connecticut 06510.
Pediatr Res. 1994 Feb;35(2):152-6. doi: 10.1203/00006450-199402000-00005.
Very few data are available regarding the decreased susceptibility of the developing kidney to anoxia. Therefore, the purpose of this study was to develop an experimental system that would allow comparison of an anoxic insult in immature and mature proximal tubule segments and to investigate the hypothesis that the developing kidney is resistant to anoxia as compared with the mature kidney. Suspensions of proximal tubules from immature (age 8-10 d) and mature (8-10 wk) rats were obtained. The purity of the tubule suspension from the immature rats was documented by villin staining. A common buffer solution was developed to compare results from the immature and mature tubules. To study the response of the tubules to anoxia, we subjected the tubule suspension from both the immature and mature rats to 15, 30, 45, and 60 min of anoxia. Lactate dehydrogenase release was measured to assess plasma membrane damage, and ATP levels were determined as an index of cellular energy. After a short anoxic insult (15 or 30 min), the percentage of lactate dehydrogenase release was not significantly different from mature tubules. After prolonged anoxia (45 and 60 min) lactate dehydrogenase release continued to increase, whereas membrane integrity stabilized in the immature tubules. ATP levels decreased in both immature and mature tubules after anoxia, but the decline of ATP was greater in the mature tubules, with a plateau at 20% of basal ATP levels as compared with 40% in the immature tubules. Therefore, the developing kidney is resistant to prolonged anoxia.
关于发育中的肾脏对缺氧敏感性降低的可用数据非常少。因此，本研究的目的是建立一个实验系统，以便比较未成熟和成熟近端小管段的缺氧损伤，并研究发育中的肾脏与成熟肾脏相比对缺氧具有抗性这一假说。获得了来自未成熟（8 - 10日龄）和成熟（8 - 10周龄）大鼠的近端小管悬浮液。通过维林染色记录未成熟大鼠小管悬浮液的纯度。开发了一种通用缓冲溶液以比较未成熟和成熟小管的结果。为了研究小管对缺氧的反应，我们将来自未成熟和成熟大鼠的小管悬浮液分别进行15、30、45和60分钟的缺氧处理。测量乳酸脱氢酶释放以评估质膜损伤，并测定ATP水平作为细胞能量的指标。在短暂缺氧损伤（15或30分钟）后，乳酸脱氢酶释放的百分比与成熟小管没有显著差异。在长时间缺氧（45和60分钟）后，乳酸脱氢酶释放持续增加，而未成熟小管中的膜完整性趋于稳定。缺氧后未成熟和成熟小管中的ATP水平均下降，但成熟小管中ATP的下降幅度更大，成熟小管中ATP水平降至基础ATP水平的20%时趋于平稳，而未成熟小管中为40%。因此，发育中的肾脏对长时间缺氧具有抗性。
