Physiological function of free D-alanine as an iso-osmotic effector in crustaceans

游离 D-丙氨酸作为甲壳类动物等渗效应物的生理功能

• 批准号: 07660278
• 负责人: ABE Hiroki
• 金额: $ 1.6万
• 依托单位: Kyoritsu Women's University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07660278/
• 关键词: iso-osmotic regulation; crustacean; D-alanine; D-amino acid; hyper-osmosis; free amino acid

Free D- and L-amino acids were determined on the various tissues of crayfish Porcambarus clarkii, marsh crab Holometopus dehaani, and shore crab Hemigrapsus penicillatus during seawater acclimation from freshwater.Along with the hyper-osmotic stress, several free amino acids increased in the muscle as well as the other tissues of these crustaceans. Of several D-amino acids found in the tissues, only D-alanine increased significantly during seawater acclimation. The ratio of D-alanine to total alanine also increased to about 50% in seawater. These data clearly indicate that D-alanine is a major osmo-effector for maintaining the tissue iso-osmotic pressure in these crustaceans.Woolly-handed crab Eriocheir japonicus, which migrates downstream during spawning in fall, did not show clear increase of free amino acids and D-alanine during seawater acclimation before summer. D-Alanine in the tissues of this crab is much higher in the individuals obtained from summer to fall than those from spring to summer. During seawater acclimation of this species obtained after summer, the increase of D-alanine was high and reached to almost the same level as that in naturally migrated individuals captured at seashore. During seawater acclimation, hemolymph showed the increase of only inorganic ions and no change of free amino acids and betaines. Thus, these data indicate that only inorganic ions are responsible for the osmotic regulation in hemolymph but D-alanine as well as other several amino acids are also responsible up to 45% of total osmolytes for the tissue iso-osmotic regulation of this species during downstream spawning migration.In this study, the physiological function of D-alanine in the tissues of crustaceans was elucidated to be as a major iso-osmotic effector. The level of D-alanine in the muscle of crayfish was also known to be maintained even after starvation in seawater and after administration of D- or L-alanine in the muscle.

在小nater鱼，沼泽螃蟹众虫，沼泽螃蟹众多的dehaani和海岸蟹半乳鼠Penicillatus上，在海水适应新淡水中的多种组织上确定游离D-氨基酸。在组织中发现的几种D-氨基酸中，在海水适应期间，只有D-丙氨酸显着增加。 D-丙氨酸与总丙氨酸的比率也增加到海水的约50％。这些数据清楚地表明，D-丙氨酸是在这些甲壳类动物中维持组织同质渗透压力的主要OSMO效应器。在秋季秋季产卵期间，在夏季夏季，秋季在秋季产卵期间，在秋季产卵期间下游迁移并未明显增加夏季夏季，在夏季夏季，在夏季，秋季在秋季产卵期间迁移了明显的增加。从夏季到秋季获得的个体，该蟹组织中的D-丙氨酸比春季到夏季的人要高得多。在夏季后获得的该物种的海水适应期间，D-丙氨酸的增加很高，达到了与在海滨捕获的自然迁移个体中的水平几乎相同的水平。在海水适应期间，血淋巴仅显示无机离子的增加，并且不变自由氨基酸和甜菜碱。因此，这些数据表明，只有无机离子负责血淋巴中的渗透调节，但D-丙氨酸以及其他几种氨基酸以及其他几种氨基酸也负责该物种在下游迁移期间该物种的组织异渗透调节的总渗透量的45％，这是在这项研究过程中的生理学作用。等值效应子。即使在海水饥饿和肌肉中的D-或L-丙氨酸给药后，也已知小龙虾肌肉中的D-丙氨酸水平也可以维持。