Arakawa S, Ito M, Tejima S
Division of Biology, Aichi Prefectural Institute of Public Health, Nagoya, Japan.
J Nutr Sci Vitaminol (Tokyo). 1988 Dec;34(6):577-85. doi: 10.3177/jnsv.34.577.
In order to understand the function of carrageenan, an indigestible polysaccharide, as a promoter of colonic tumors induced by 1,2-dimethylhydrazine (DMH), molecular weight distribution of fecal carrageenan and amounts of fecal bile acids in rats given carrageenan and DMH treatment were examined. Gel filtration pattern on Sephacryl S-300 of fecal carrageenan was very similar to that of feeding carrageenan, and carrageenan ingested was quantitatively excreted in feces. Hexafluoroisopropyl ester-trifluoroacetyl derivatives of fecal bile acids were analyzed by gas chromatography on QF-1. Although there was a decreased concentration of deoxycholic acid and total bile acids in carrageenan-fed rats compared to control rats, no difference in the daily output was found because carrageenan ingestion increases fecal output. Significant increased concentration and daily output of lithocholic acid, a tumor-promoter, by feeding carrageenan were found. Thus, it was suggested that the promoting effect of carrageenan on colon tumorigenesis by DMH may be mediated by increased excretion of lithocholic acid and may not participate in degradation of carrageenan ingested.
为了解不可消化的多糖卡拉胶作为1,2 - 二甲基肼（DMH）诱导的结肠肿瘤促进剂的作用，研究了给予卡拉胶和DMH处理的大鼠粪便中卡拉胶的分子量分布及粪便胆汁酸含量。粪便卡拉胶在Sephacryl S - 300上的凝胶过滤图谱与喂食卡拉胶的图谱非常相似，摄入的卡拉胶定量排泄于粪便中。粪便胆汁酸的六氟异丙酯 - 三氟乙酰衍生物通过QF - 1气相色谱法进行分析。与对照大鼠相比，喂食卡拉胶的大鼠中脱氧胆酸和总胆汁酸浓度降低，但由于卡拉胶摄入增加了粪便排出量，每日排出量未发现差异。发现喂食卡拉胶可使肿瘤促进剂石胆酸的浓度和每日排出量显著增加。因此，提示卡拉胶对DMH诱导的结肠肿瘤发生的促进作用可能是通过石胆酸排泄增加介导的，且可能不参与摄入卡拉胶的降解。
