Behavior in the rat of a transport-specific, bicyclic amino acid. Hypoglycemic action.
Behavior in the rat of a transport-specific, bicyclic amino acid. Hypoglycemic action.
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运输特异性双环氨基酸在大鼠中的行为。
DOI：
10.1016/s0021-9258(18)91790-4
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发表时间：
1969
期刊：
影响因子：
--
通讯作者：
A. Cullen
中科院分区：
文献类型：
--
作者：
H. Christensen;A. Cullen
一种模型氨基酸，2 -氨基双环[2,2,1]庚烷-2-羧酸，对具有大极性侧链的中性氨基酸的Na+非依赖性转运机构具有高度特异性，已被证明在完整的大鼠体内排泄缓慢，如果有的话，代谢的程度非常小，并且在组织中积累，特别是在胰腺中。这种物质的两种异构体形式中的一种在大鼠体内保留的时间比另一种长，尽管它们都被组织吸收，并且都可能从肾小球滤液中被吸收。腹腔注射每公斤体重5 ~ 10毫摩尔时，尿中几种普通氨基酸的排泄量增加。此外，几种氨基酸的血浆水平下降，尽管苯丙氨酸的水平可能有所增加。在肾上腺切除的大鼠中，这些影响似乎至少同样严重，2 -氨基双环[2,2,1]庚烷-2-羧酸给药容易使大鼠俯伏。研究发现，这种注射剂可以降低血糖，在首次接受甲苯丁胺治疗的动物中效果尤其明显。效果较亮氨酸持久。这种行为使我们提出胰岛素分泌的刺激可能是通过在战略位置的转运受体位点结合而触发的。然而，分离的、完整的大鼠膈肌对2-氨基双环[2,2,1]庚烷-2-羧酸的摄取不受胰岛素刺激。
A model amino acid, 2-aminobicyclo[2,2,1]heptane-2-carboxylic acid, highly specific to the Na+-independent transport agency for neutral amino acids with large apolar side chains, has been shown to be excreted slowly by the intact rat, to be metabolized to a very small extent if at all, and to be accumulated by tissues, especially by pancreas. One of the two isomeric forms of this substance was retained in the rat longer than the other, although both were taken up by tissues, and both presumably were resorbed from the glomerular filtrate. When 5 to 10 mmoles per kg of body weight were injected intraperitoneally, the urinary excretion of several ordinary amino acids was increased. In addition, the plasma levels of several amino acids were decreased, although that of phenylalanine may have increased. These effects appeared to be at least as severe in adrenalectomized rats, which were easily prostrated by 2-aminobicyclo[2,2,1]heptane-2-carboxylic acid administration. The injections were found to lower the blood glucose, the effect being especially strong in animals first treated with tolbutamide. The effect was more prolonged than that of leucine. This behavior leads us to propose that the stimulation of insulin secretion may be triggered by binding at strategically situated transport receptor sites. The uptake of 2-aminobicyclo[2,2,1]heptane-2-carboxylic acid by the isolated, intact rat diaphragm was, however, not stimulated by insulin.