GROWTH PATTERNS AND CLINICAL CHANGES IN RATS FED NIH 07 AND NTP 2000 DIETS

NIH-07开放式配方非精制饮食已被选为 1980年以来对NTP啮齿动物的研究。这种饮食是由20多个人制定的 年前用于繁殖、哺乳和繁殖中的啮齿动物生长 殖民地。这种饮食含有大约24%的蛋白质，5%的脂肪和 在长期研究中，3.5%的纤维可能不是大鼠的最佳饮食，而且 一些成分，如蛋白质、钙和磷浓度 可能会增加慢性病的严重程度。在经历了6年的 一种新的试验饲料不同配方的试验 配方为NTP-2000开放式配方非纯净型日粮 用于毒理学研究中的啮齿动物。这种饮食有很大的不同 来自NIH-07饮食，含有大约15%的蛋白质，8.5%的脂肪和 纤维含量为9.5%。这项研究的目的是比较1)生长模式， 2)血液学和临床化学指标，3)器官重量和 4)Fischer 344(F344)大鼠的病变发生率和严重程度。 NIH-07和NTP-2000饮食13周。每组25名男性和女性 6周龄F344大鼠饲喂NIH-07或NTP-2000饲料13次 几周。测定了饲料消耗量和用水量，并 12周后进行血液学和临床生化检查。 治疗13周后，大鼠身体解剖，主要器官 主要脏器的称重和组织病理学变化通过 光学显微镜。两者的增长模式基本上是相同的 节食。饲料消耗量略高，耗水量略高。 而饲喂NTP-2000饲料的大鼠则略低。没有什么不同 在饲喂上述饲料的两组之间的血液学参数。 饲喂NTP-2000饲料的雄性和雌性BUN值显著 由于这种饮食的蛋白质含量较低，所以摄入量较低。胆固醇水平 男性的5‘核苷酸酶和碱性磷酸酶水平 而喂食NTP-2000的雌性由于脂肪含量较高而略高 关于饮食的问题。然而，饲喂NTP-2000日粮的组的甘油三酯水平 较低，可能与NTP-2000纤维含量较高有关 节食。饲喂NTP-2000的雄性和雌性大鼠的肝和肾重量 饮食水平显著降低，可能是因为蛋白质摄入量较低 药物代谢酶的相关变化。肾上腺重量是 在喂食新饮食的组中显著降低。NTP-2000饮食 预防肾钙质沉着症，降低发病率和严重程度 F344大鼠肾病和心肌病常见病变 为期13周的研究。这些结果表明，NTP-2000饮食是 对老鼠的生长和维持是足够的，并且似乎可以防止或 降低与饮食和年龄相关的损伤的严重程度。

NIH-07 open formula nonpurified diet has been the selected diet for the NTP rodent studies since 1980. This diet was formulated more than 20 years ago for reproduction, lactation and growth of rodents in breeding colonies. This diet which contains approximately 24% protein, 5% fat and 3.5% fiber may not be an optimal diet for rats in long-term studies, and some components such as protein, calcium and phosphorus concentrations may be increasing the severity of chronic diseases. After 6 years of experimentation with different formulations of experimental diets, a new diet designated as NTP-2000 open formula nonpurified diet was formulated for rodents in toxicology studies. This diet is substantially different from NIH-07 diet and contains approximately 15% protein, 8.5% fat and 9.5% fiber. The purpose of this study was to compare 1) growth patterns, 2) hematology and clinical chemistry parameters, 3) organ weights and 4) incidence and severity of lesions in Fischer 344 (F344) rats fed the NIH-07 and NTP-2000 diets for 13 weeks. Groups of 25 male and female F344 rats of 6 weeks of age were fed NIH-07 or NTP-2000 diet for 13 weeks. Feed consumptions and water consumptions were determined and hematology and clinical chemistry evaluations were done at 12 weeks. After 13 weeks of treatment the rats were necropsied, major organs were weighed and histopathologic changes in major organs were evaluated by light microscopy. The growth patterns were essentially same for both diets. The feed consumptions were slightly higher and water consumptions were slightly lower for rats fed NTP-2000 diet. there were no differences in hematological parameters between the groups fed the above diets.The BUN values for males and females fed NTP-2000 diet were significantly lower due to lower protein content of this diet. The cholesterol level in males, and 5'nucleotidase and alkaline phosphatase levels in males and females fed NTP-2000 were slightly higher due to higher fat content of the diet. However, the triglyceride levels in groups fed NTP-2000 diet were lower and it may be related to higher fiber content of the NTP-2000 diet. The liver and kidney weights of male and female rats fed NTP-2000 diet were significantly lower possibly due to lower protein consumption associated changes in drug metabolizing enzymes. The adrenal weights were significantly lower in groups fed the new diet. The NTP-2000 diet prevented nephrocalcinosis, decreased the incidence and severity of nephropathy and cardiomyopathy, the common lesions of F344 rats in 13-week studies. these results indicate that the NTP-2000 diet is adequate for growth and maintenance of rats and appears to prevent or decrease the severity of diet-and-age associated lesions.