三种蛋白质对大鼠镉吸收的影响。

Effects of three proteins on absorption of cadmium in rats.

作者信息

Kojima S, Kiyozumi M, Mishima M, Honda T, Nakagawa M

出版信息

Toxicology. 1985 Feb;34(2):161-71. doi: 10.1016/0300-483x(85)90165-9.

Abstract

The effects of 3 proteins on the gastrointestinal absorption of cadmium were studied. Glycinin and ovalbumin significantly decreased cadmium in liver and the total cadmium in the tissues of rats following a single oral administration of cadmium. In addition, in rats fed continuously with the experimental diets containing cadmium together with proteins, glycinin and ovalbumin significantly decreased the contents of cadmium in the tissues. These results show that the proteins depressed the gastrointestinal absorption of cadmium. Moreover, the effects of cadmium on various digestive enzymes for proteins and the pepsin or pepsin-pancreatin digestion of the proteins were examined. As a result it is likely that the inhibitory effect of cadmium on the intestinal digestion of these proteins is one of the causes of the inhibitory effects of the proteins on the intestinal absorption of cadmium in rats. The undigested oligopeptides may decrease the amount of free cadmium available to be absorbed from the intestine by binding cadmium itself, resulting in decreased intestinal absorption of cadmium.

摘要

研究了3种蛋白质对镉胃肠道吸收的影响。单次口服镉后，大豆球蛋白和卵清蛋白显著降低了大鼠肝脏中的镉以及组织中的总镉含量。此外，在持续喂食含镉和蛋白质的实验性日粮的大鼠中，大豆球蛋白和卵清蛋白显著降低了组织中的镉含量。这些结果表明，这些蛋白质抑制了镉的胃肠道吸收。此外，还研究了镉对各种蛋白质消化酶以及蛋白质的胃蛋白酶或胃蛋白酶-胰蛋白酶消化的影响。结果表明，镉对这些蛋白质肠道消化的抑制作用可能是蛋白质对大鼠肠道镉吸收产生抑制作用的原因之一。未消化的寡肽可能通过与镉本身结合而减少可从肠道吸收的游离镉量，从而导致肠道对镉的吸收减少。