Characteristics of amino acid metabolism by isolated alveolar type II cells.
Characteristics of amino acid metabolism by isolated alveolar type II cells.
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分离的II型肺泡细胞的氨基酸代谢特征。
DOI：
10.3109/01902148409069669
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发表时间：
1984
影响因子：
1.7
通讯作者：
R. D. Greenleaf
中科院分区：
文献类型：
--
作者：
R. D. Greenleaf
肺的 II 型肺泡细胞对于产生脂蛋白表面活性剂很重要。大多数关于 II 型细胞代谢的研究都集中在磷脂代谢的脂质前体上。表面活性剂含有独特的脱辅基蛋白；然而，对于 II 型细胞的氨基酸代谢知之甚少。使用密度梯度离心然后离心淘洗分离II型细胞。细胞孵育 2 小时后，测量丙氨酸 (Ala)、亮氨酸 (Leu)、缬氨酸 (Val) 和苯丙氨酸 (Phe) 掺入蛋白质和脂质以及氧化成 CO2 的情况。对于丙氨酸代谢，丙氨酸总放射性的 22% 被掺入蛋白质，20% 掺入脂质，58% 氧化为 CO2。对于亮氨酸，51% 被结合到蛋白质中，23% 被结合到脂质中，22% 被氧化成 CO2。缬氨酸代谢产生的放射性物质的 50% 转化为蛋白质，5% 转化为脂质，47% 氧化为 CO2。然而，几乎所有（95%）的苯丙氨酸仅用于蛋白质合成。嘌呤霉素和放线菌酮减少了丙氨酸、亮氨酸和苯丙氨酸的蛋白质合成，但对丙氨酸和亮氨酸代谢为脂质或二氧化碳的影响很小。降血脂药物氯贝丁酯抑制氨基酸代谢的各个方面。总之，II 型细胞氨基酸代谢的调节与骨骼肌和脂肪组织细胞的氨基酸代谢类似，但与肝细胞相反，II 型细胞容易氧化缬氨酸并利用亮氨酸进行脂质和蛋白质合成。
Alveolar type II cells of the lung are important in producing the lipoprotein surfactant. Most studies about metabolism in type II cells have focussed on lipid precursors for phospholipid metabolism. Surfactant contains a unique apoprotein; yet relatively little is known about the metabolism of amino acids by type II cells. Type II cells were isolated using density gradient centrifugation followed by centrifugal elutriation. Alanine (Ala), leucine (Leu), valine (Val), and phenylalanine (Phe) incorporation into protein and lipid and oxidation to CO2 was measured after the cells were incubated for 2 h. For alanine metabolism, 22% of total radioactivity from alanine was incorporated into protein, 20% into lipid, and 58% oxidized to CO2. For leucine, 51% was incorporated into protein, 23% into lipid, and 22% oxidized to CO2. Fifty percent of radioactivity from valine metabolism was incorporated into protein, 5% into lipid, and 47% oxidized to CO2. Virtually all (95%) of phenylalanine, however, was utilized for protein synthesis only. Puromycin and cycloheximide decreased protein synthesis from Ala, Leu, and Phe but had little affect on Ala and Leu metabolism to lipid or CO2. The hypolipidemic drug clofibrate inhibited all aspects of amino acid metabolism. In summary, type II cell amino acid metabolism is regulated similar to that of cells from skeletal muscle and adipose tissue, but in contrast to hepatocytes, type II cells readily oxidize valine and utilize leucine for lipid as well as protein synthesis.
鉴定原代培养物中 II 型肺细胞合成的特定蛋白质。
DOI：
10.1042/bj2100607
发表时间：
1983
期刊：
The Biochemical journal
影响因子：
--
作者：
Wartell,SA;Nafe,CK;Watkins,CA;Rannels,DE
通讯作者：
Rannels,DE