氨基酸向雌激素预处理子宫的转运。通过预孵育增强摄取。

Transport of amino acids into the oestrogen-primed uterus. Enchancement of the uptake by a preliminary incubation.

作者信息

Riggs T R, Pan M W

出版信息

Biochem J. 1972 Jun;128(1):19-27. doi: 10.1042/bj1280019.

DOI:10.1042/bj1280019

PMID:5085566

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC1173565/

Abstract

Preincubation of the immature rat uterus under physiological conditions was found to increase its subsequent ability to transport alpha-aminoisobutyric acid, l-proline, l-alanine and 1-aminocyclopentanecarboxylic acid. Uptakes of l-valine, l-phenylalanine and l-leucine were not affected. With alpha-aminoisobutyric acid, a doubling of the uptake could be obtained after a 3-5h preincubation period. Uteri from oestradiol-primed rats gave increases similar to those found in tissues from untreated animals. In both cases the preincubation increased the V(max.) of alpha-aminoisobutyric acid uptake but did not affect the K(m). 2. The conditions during the preincubation period determined the increase in subsequent uptake of alpha-aminoisobutyric acid. No increase in uptake was found if the preincubation was carried out at 1 degrees C, in the presence of cyanide or dinitrophenol, under anaerobiosis or with a concentration of puromycin that depressed incorporation of l-leucine into protein by 95%. The puromycin was also shown to prevent the increase in V(max.) normally found after the preincubation period. In addition, no increase was found if Na(+) was omitted from the preincubation medium. Other inorganic ions had smaller effects. 3. The uptake of alpha-aminoisobutyric acid by uteri before and after a preincubation period showed the same general patterns of sensitivity to competitive inhibitors, K(+), pH, temperature and 2,4-dinitrophenol. 4. The results suggest that the preincubation leads to an increase in a protein component of the ;A system' for amino acid transport in the uterus, and that metabolic energy is required for the reactions involved.

摘要

研究发现，在生理条件下对未成熟大鼠子宫进行预孵育，可增强其随后转运α-氨基异丁酸、L-脯氨酸、L-丙氨酸和1-氨基环戊烷羧酸的能力。L-缬氨酸、L-苯丙氨酸和L-亮氨酸的摄取不受影响。对于α-氨基异丁酸，预孵育3 - 5小时后摄取量可增加一倍。经雌二醇预处理的大鼠子宫的增加情况与未处理动物组织中的相似。在这两种情况下，预孵育均增加了α-氨基异丁酸摄取的V(max.)，但不影响K(m)。2. 预孵育期间的条件决定了随后α-氨基异丁酸摄取的增加。如果在1℃、存在氰化物或二硝基苯酚、厌氧条件下或在嘌呤霉素浓度能使L-亮氨酸掺入蛋白质减少95%的情况下进行预孵育，则摄取量不会增加。嘌呤霉素还被证明可阻止预孵育期后通常出现的V(max.)增加。此外，如果预孵育培养基中省略Na(+)，也不会有增加。其他无机离子的影响较小。3. 预孵育前后子宫对α-氨基异丁酸的摄取对竞争性抑制剂、K(+)、pH、温度和2,4-二硝基苯酚表现出相同的一般敏感性模式。4. 结果表明，预孵育导致子宫中氨基酸转运“A系统”的一种蛋白质成分增加，并且所涉及的反应需要代谢能量。