Richter B D, Schneeman B O
J Nutr. 1987 Feb;117(2):247-52. doi: 10.1093/jn/117.2.247.
Rats were fed purified diets which provided 24% protein from casein (C), soy protein isolate (SPI), or egg white (EW) for 18 mo. Groups of rats were killed at 3, 6, 12 and 18 mo; the pancreata were removed and examined histologically for occurrence of atypical nodules. The weight, protein, DNA, trypsin and chymotrypsin concentrations of the pancreas at each period were measured. Over the entire experimental period, body weight did not differ among groups. Pancreatic weight, protein and trypsin activity were highest in the EW group, followed by the SPI group, and lowest in the C group. Chymotrypsin activity was significantly higher in the EW and SPI groups than the C group. DNA content did not differ significantly among groups over the entire experimental period, although it was elevated in the SPI or EW groups compared to the C groups at some of the time periods. Only one microscopic nodule was observed in all of the animals; it was found at 3 mo in the pancreas from an animal fed EW. Overall, the results suggest that the elevation in enzyme activity and pancreatic weight associated with long-term consumption of EW and SPI did not result in development of pancreatic lesions in rats.
给大鼠喂食纯化日粮，日粮中酪蛋白（C）、大豆分离蛋白（SPI）或蛋清（EW）提供24%的蛋白质，持续18个月。在3、6、12和18个月时处死几组大鼠；取出胰腺并进行组织学检查，以观察非典型结节的发生情况。测量每个时期胰腺的重量、蛋白质、DNA、胰蛋白酶和糜蛋白酶浓度。在整个实验期间，各组大鼠的体重没有差异。胰腺重量、蛋白质和胰蛋白酶活性在EW组最高，其次是SPI组，在C组最低。EW组和SPI组的糜蛋白酶活性显著高于C组。在整个实验期间，各组的DNA含量没有显著差异，尽管在某些时间段，SPI组或EW组的DNA含量相对于C组有所升高。在所有动物中仅观察到一个显微镜下可见的结节；它是在一只喂食EW的动物的胰腺中于3个月时发现的。总体而言，结果表明，长期食用EW和SPI导致的酶活性和胰腺重量升高并未导致大鼠胰腺病变的发生。
