Electrical activity across human foetal small intestine associated with absorption processes.
Electrical activity across human foetal small intestine associated with absorption processes.
复制标题
人类胎儿小肠的电活动与吸收过程相关。
作者：
R. Levin;O. Koldovský;J. Hošková;V. Jirsová;J. Uher
可以测量跨动物和人小肠壁的电位差，极性为浆膜对粘膜为正。当将主动转移的己糖或氨基酸加入到浸浴肠粘膜表面的流体中时，观察到该内源性或基础透壁电位差（即己糖或氨基酸转移电位差）的快速增加（Schachter和Britten，1961年，大鼠;巴里、Dikstein、马修斯、Smyth和Wright，1964年，大鼠; Schultz和Zalusky，1965年，兔子; Levin，1966，在牛蛙中; Grady，MacGaffey，摩尔和查尔默斯，1966，在人中）。尽管对大鼠空肠中产电机制的确切性质仍存在疑问（巴里、Smyth和Wright，1965），但对家兔回肠的研究表明，己糖或氨基酸的主动转移与钠离子运动增加有关，钠离子运动增加产生转移电势差（Schultz和Zalusky，1965）。所有关于哺乳动物产电己糖和氨基酸转移系统的研究都是在成熟动物的肠道上进行的。没有关于胎儿动物（Wilson和Lin，1960）或胎儿人（Koldovsky、Heringova、Jirsova、Jirasek和Uher，1965）肠道中存在的氨基酸和己糖转移机制的产电性数据。哈德逊和Levin（1966）最近研究了鸡在体外发育过程中小肠电活动的个体发生。他们表明，鸡胚肠中的活性己糖转移系统（Holdsworth和Wilson，1967）是产电的，因为只有主动转运的糖才能产生转移电位。本文用类似的体外技术研究了人胎儿小肠电活动的个体发生。还进行了实验以研究某些氨基酸对
An electrical potential difference can be measured across the wall of animal and human small intestine, the polarity being serosa positive to mucosa. When actively transferred hexoses or amino acids are added to the fluid bathing the intestinal mucosal surface, a rapid increase in this endogenous or basal transmural potential difference is observed, i.e. an hexose or amino acid transfer potential difference (Schachter and Britten, 1961, in the rat; Barry, Dikstein, Matthews, Smyth, and Wright, 1964, in the rat; Schultz and Zalusky, 1965, in the rabbit; Levin, 1966, in the bullfrog; Grady, MacGaffey, Moore, and Chalmers, 1966, in man). Although there is still doubt as to the exact nature of the electrogenic mechanisms in rat jejunum (Barry, Smyth, and Wright, 1965) studies on rabbit ileum indicate that the active transfer of hexose or amino acid is linked with an increased movement of sodium ions which generates the transfer potential difference (Schultz and Zalusky, 1965). All studies on the electrogenic hexose and amino acid transfer systems in mammals have been conducted on intestine from mature animals. No data are available on the electrogenicity of transfer mechanisms for amino acids and hexoses present in the intestines of foetal animals (Wilson and Lin, 1960) or foetal humans (Koldovsky, Heringova, Jirsova, Jirasek, and Uher, 1965). Hudson and Levin (1966) have recently studied the ontogeny of electrical activity across the small intestine in vitro during the development of the chick. They showed that the active hexose transfer system in the chick embryonic intestine (Holdsworth and Wilson, 1967) was electrogenic, for only actively transported sugars gave transfer potentials. In this paper the ontogeny of electrical activity across small intestine from human foetuses has been studied using a similar in vitro technique. Experiments have also been undertaken to investigate the influence of some amino acids on