丹宁生物活化理论及其应用 Ⅱ.丹宁生物活化理论的基本点及其实践应用

根据“丹宁生物活化假设”及实验设计要求,以丹宁酸为材料研究了丹宁在家兔体内的生物活化现象;以栎叶丹宁为材料研究了丹宁在牛体内生物活化过程。结果表明,家兔口服丹宁酸中毒后,在尿中检出连苯三酚和没食子酸等酚类化合物,而在胃肠道仍存留部分未被降解的丹宁酸;牛采食栎叶或投服栎叶丹宁后在前胃经生物降解产生多种低分子酸类化合物,并能在血、尿、胃肠内容物中检出一二三元酚,未能检出栎叶丹宁。给牛口服连苯三酚引起与栎叶丹宁相同的临床症状和病理变化,肝肾组织的超微结构也呈一致变化。因此,作者认为丹宁中毒的主要因素是其生物降解产物,而不是丹宁本身,丹宁中毒的实质是低分子酚类化合物引起的中毒。本文在阐述的“丹宁生物活化”新理论及其基本点的基础上,重新阐述了牛栎叶丹宁中毒的发病机理。改进的综合防治技术,提高了治愈率和预防效果。

THEORY OF TANNIN BIOACTIVATION AND ITS APPLICATION II. Confirmation of Tannin Bioactivation Hypothesis by Experiments

Based on "Tannin Bioactivation Hypothesis" and the requirements of experimental design as well as with Tannic acid as the material, this paper deals with the bioactiviting process of Tai.nic acid in single stomach animal -rabbits, and also, with oak leaf Tannin as the material, that in the ruminant'----cattle. And eventually, the "hypothesis" has been confirmed.The resultsfrom the experiments indicate in the following.( 1 ) Gallic acid, pyrogallol and other phenolic compounds in rabbit urine were identified after the rabbits were in toxicosis when treated with oral Tannic acid, while some undergradated Tannic acid remained in the gastrointestinal tract. ( 2 ) Many phenolic compunds with low molecular weight were produced through biological degradation in the four stomachcs after the cattle took in oak lea vcs or were given with oak leaf Tannin.As a result , mono- ,di-and tri-phenolatcs could be identified in blood urine and the contents in rumen and intestines of the cattle, but on oak leaf Tannin could be found. Similar clinical symptoms and histopathological changes might be caused by oral administration of pyrogallol to the cattle just as those caused by oak leaf Tannins given to them, Also, the uniform changes occurcd in super - microstructures in hcpar and kidney tissue identified by electromicroscope observation. Based on the above facts, the author gives a negative answer to the viewpoint that Tannins arc directly absorbed through the gastonilestinal tract. The author holds that the primary factor of Tannin toxicosis is not caused by Tannin itself but by its metablets, and that the nature of Tannin toxicosis is the phenolic compound with low melecular weight that cause toxicosis. At the same time,the author first states the new theory of Tannin Bioactivation.