Studies on the Accumulation Mechanism and Metabolism of D-Alanine in Aquatic Animals

最近的研究表明，一些d -氨基酸在海洋动物中分布相当广泛。本研究旨在积累更多关于丙氨酸d -对映体在水生动物体内分布的信息。外周目、腔肠目、白蛉目、Nemertinea目和原脊索目中均未检测到d -丙氨酸。含d -丙氨酸的种属于软体动物门的尾鳃亚纲，节肢动物门的十足亚纲，棘皮动物门的真棘皮亚纲，缺乏d -丙氨酸的种属于新胃足目，软体动物门的翼形亚纲和头足纲，节肢动物门的胸足纲和等足纲，棘皮动物门的拟鱼纲和全鳍鱼纲。用粗上清法测定了不同种类海鱼（haalitis diversi, turbanshell, Tectus maximus, manplex echo, Charonia sauliae sauliae, Rapana venosa，普通章鱼，日本普通鱿鱼和ocellate puffer）组织中丙氨酸消旋酶在两个方向（d -丙氨酸到l -丙氨酸和l -丙氨酸到d -丙氨酸）的活性。在L-to-D方向上，大霉的中肠活性为21.3 μmol /h，在D-to-L方向上为26.3 μmol /h。在腹足动物的许多其他物种中，除蛇外，丙氨酸消旋酶的活性是双向的。丙氨酸消旋酶在缺乏d -丙氨酸（只有l -丙氨酸）的常见章鱼、日本普通鱿鱼和梭子鱼的肝脏和肾脏中均有d -到l方向的活性。

Recent investigations show rather wide distribution of some D-amino acids in marine animals. The present studies were planned to accumulate more information on the distribution of D-enantiomer of alanine in aquatic animals.No measurable D-alanine could be detected in Periphery, Coelenterata, Platyhelminthes, Nemertinea and Prochordata species. D-Alanine-containing species belong to the order Archaegastropoda and Mesogastropoda, the subclass Eulamellbranchia in the phyla, Mollusca, the order Decapoda in the phyla Arthropoda and the subclass Euechinoidea in the phyla Echinodermata and D-alanine lacking species to the order Neogastropoda, the subclass Pteriomorphia and the class Cephalopoda in the phyla Mollusca, the order thoracica and Isopoda in the phyla Arthropoda, the class Euasteroidea and Holothuroidea in the phyla Echinodermata.Crude supernatant from tissues of Haliotis diversi color diversicolor, turban shell, Tectus maximus, Manoplex echo, Charonia sauliae sauliae, Rapana venosa, common octopus, Japanese common squid and ocellate puffer was examined for alanine racemase activity in both direction (D-alanine to L-alanine and L-alanine to D-alanine). The activity in mid gut glad of T.maximus was 21.3 μmol of product formed g wet tissue/h in the L-to-D direction and 26.3 in the D-to-L direction. In many tissues of the other species in Gastropoda except R.venosa alanine racemase activity occurs in both direction. Alanine racemase activity in the only D-to-L direction is found in liver and kidney of common octopus, Japanese common squid and ocellate puffer, which are D-alanine-lacking species (only L-alanine is present).