NEPHROCALCINOSIS IN F344 RATS FED NIH-31 DIET

这个项目的目标是研究和发展 确定皮质髓管内病变的原因 饲喂NIH-31或NIH-31的雌性F344大鼠肾钙沉积症(NC)的观察 NIH-07开放式配方饮食。在1986年初的一次校内研究中 在组织学上观察到42和56岁的大脑皮质有严重的NC。 日龄对照组和处理组雌性F344/Cr1BR大鼠 分别饲喂NIH-31饲料15天和28天。在28年前 几天后，他们就可以获得商业啮齿动物的饮食。女性 F344大鼠被认为易患NC；然而， 观察到的损伤比以前看到的更严重。 对NIH-31饮食的分析与处方一致 营养价值，包括钙、磷、镁和维生素。D.不含雌激素 通过生物活性测定证明了其活性。在大鼠体内观察到NC 给予NIH-31和去离子水或自来水。完成的平行研究 第二个设施还发现了42天和56天龄的NC。二 来自同一供应商的F344/N大鼠群体，但维持在 对2个不同饲料生产厂家的NIH-31进行了比较。 两个群体在42日龄时都发展为NC。肾脏来自 长期研究期间饲喂NIH-07的F344/N大鼠 毒理学方案进行了检查。NC的最低证据是 在20周以上的老鼠身上发现。F344/N大鼠的实验研究 正在跟踪这一病变在一段时间内的进展 一年。此外，正在计划进行研究，以检查 可能存在的植物雌激素类物质的可能作用 在某些饲料中的含量取决于它们的来源和作物年份。

The objective of this project is to study the development of and to identify the cause of corticomedullary intratubular nephrocalcinosis (NC) observed in female F344 rats fed NIH-31 or NIH-07 open formula diets. In early 1986 in an intramural study severe NC was observed histologically in the cortex of 42 and 56 day old control and treated female F344/Cr1BR rats which had been fed NIH-31 diet for 15 and 28 days respectively. Prior to 28 days of age they had access to a commercial rodent diet. Female F344 rats are recognized as being prone to NC; however, the lesions observed were more severe than had been seen previously. Analysis of the NIH-31 diet was consistent with the prescribed nutrient values, including Ca, P, Mg, and Vit. D. No estrogenic activity was demonstrated by bioassay. NC was observed in rats given NIH-31 and deionized or tap water. Parallel studies done in a second facility also revealed NC at 42 and 56 days of age. Two colonies of F344/N rats from the same supplier but maintained on NIH-31 from 2 different feed manufacturers were compared. Both colonies developed NC by 42 days of age. Kidneys from F344/N rats fed NIH-07 during long term studies in the National Toxicology Program were examined. Minimal evidence of NC was found in rats more than 20 weeks of age. A study of F344/N rats is underway to follow the progress of this lesion over a period of one year. Further, studies are being planned to examine the possible role of phytoestrogenic substances which may be present in certain feed stuffs depending on their origin and crop year.