POLYAMINE METABOLISM AND UPTAKE DURING PHASEOLUS-VULGARIS LECTIN, PHA-INDUCED GROWTH OF RAT SMALL-INTESTINE
POLYAMINE METABOLISM AND UPTAKE DURING PHASEOLUS-VULGARIS LECTIN, PHA-INDUCED GROWTH OF RAT SMALL-INTESTINE
复制标题
DOI：
10.1159/000200409
复制
发表时间：
1990-01-01
期刊：
影响因子：
3.2
通讯作者：
PUSZTAI, A
中科院分区：
文献类型：
--
作者：
BARDOCZ, S;GRANT, G;PUSZTAI, A
菜豆凝集素(PHA)可促进大鼠小肠的增生和肥大生长。在这种生长之前，多胺在小肠中迅速积累。然而，由于凝集素对多胺的原位生物合成几乎没有影响，因此大多数多胺肯定来自胞外来源。为了探讨多胺的来源，我们测定了大鼠在体小肠对多胺的腔内摄取和基侧转运。腔内多胺摄取呈明显的被动扩散、非饱和、线性依赖的浓度依赖关系，其幅度不受PHA的刺激。相比之下，腹腔注射的14种碳多胺可能被转运系统摄取(S)。此外，当PHA刺激小肠生长时，基底外侧多胺转运呈时间依赖性地被刺激。然而，与在组织明显生长之前发现多胺积累的发现一致，PHA对多胺运输系统的刺激也先于小肠生长。肠腔因子刺激多胺转运可能是肠道适应的一般机制。
Kidney bean lectin, PHA, stimulated the hyperplastic and hypertrophic growth of rat small intestine. This growth was preceded by a rapid accumulation of polyamines in the small intestine. However, since the lectin had little effect on in situ polyamine biosynthesis, most of the polyamines must have been of extracellular origin. To investigate the source of polyamines, both the luminal uptake and basolateral transport of polyamines by the rat small intestine were measured in vivo. Luminal polyamine uptake was apparently by passive diffusion, non-saturable, linearly dependent on concentration and its extent was not stimulated by PHA. In contrast, 14 C-polyamines injected intraperitoneally were probably taken up by a transport system (s). Moreover, basolateral polyamine transport was stimulated in a time-dependent manner when small intestinal growth was stimulated by PHA. However, in keeping with the finding of polyamine accumulation prior to demonstrable growth of the tissue, stimulation by PHA of the polyamine transport system also preceded small intestinal growth. Stimulation of polyamine transport by luminal factors is possibly a general mechanism involved in intestinal adaptation.