Physiological roles of free D- and L-alanine in the crayfish Procambarus clarkii with special reference to osmotic and anoxic stress responses
Physiological roles of free D- and L-alanine in the crayfish Procambarus clarkii with special reference to osmotic and anoxic stress responses
复制标题
DOI：
10.1016/s1095-6433(02)00006-5
复制
发表时间：
2002-04-01
影响因子：
2.3
通讯作者：
Abe, H
中科院分区：
文献类型：
--
作者：
Fujimori, T;Abe, H
在从淡水到17ppt和25ppt海水的高盐胁迫下，克氏原虾在肌肉和肝胰腺中大量积累D-丙氨酸和L-丙氨酸以及甘氨酸、L-谷氨酰胺和L-脯氨酸。在所有氨基酸中，肌肉中D-丙氨酸和L-丙氨酸的增幅最高，从淡水到25ppt海水分别增加6.8倍和5.4倍。这些结果表明，D-丙氨酸和L-丙氨酸都是迄今为止研究过的小龙虾和其他甲壳类动物中最有效的细胞内等渗调节物质。在淡水、17ppt和25ppt海水中，在低于0.1 mg/L溶氧12h的缺氧胁迫下，肌肉中的三磷酸腺苷在所有盐度水平上都显著下降，在海水中几乎耗尽。随着肌肉糖原水平的降低，各盐度水平肌肉、肝胰腺和血淋巴中的L-乳酸显著增加，提示L-乳酸通过血淋巴从肌肉进入肝胰腺。在低氧条件下，肌肉和肝胰腺中的D-丙氨酸和L-丙氨酸在各盐度水平下均显著增加。海水中的增幅远远高于淡水中的增幅。因此，D-丙氨酸和L-丙氨酸在该物种的长期厌氧过程中都可能是厌氧的最终产物。(C)2002 Elsevier Science Inc.保留所有权利。
Under hyper-salinity stress from freshwater to 17 and 25 ppt seawater, red swamp crayfish Procambarus clarkii largely accumulated D- and L-alanine together with glycine, L-glutamine, and L-proline in both muscle and hepatopancreas. The increases Of D- and L-alanine in muscle were the highest in all amino acids and reached 6.8- and 5.4-fold, respectively, from freshwater to 25 ppt seawater. These results indicate that both D- and L-alanine are the most potent osmolytes for intracellular isosmotic regulation in crayfish as well as other crustaceans thus far examined. Under anoxia stress below 0.1 mg/l dissolved oxygen for 12 h and subsequent recovery in normoxia for 12 h in freshwater, 17 and 25 ppt seawater, muscle ATP decreased dramatically in all salinity levels and almost depleted in seawater. Along with the decrease of muscle glycogen level, the significant increase Of L-lactate was found in muscle, hepatopancreas, and hemolymph for each salinity level, suggesting the transport Of L-lactate from muscle into hepatopancreas via hemolymph. Under anoxia, D- and L-alanine also largely increased in both muscle and hepatopancreas for each salinity level. The increase was much higher in seawater than in freshwater. Thus, both D- and L-alanine are possible to be anaerobic end products during prolonged anaerobiosis of this species. (C) 2002 Elsevier Science Inc. All rights reserved.