Study on a new defense system in higher animals

1996年，Natori等人，发现L-多巴-谷胱甘肽共轭物作为一种新的抗菌物质在肉蝇受伤。这种物质产生过氧化氢杀灭微生物，这表明昆虫的一种新的防御系统，本研究旨在探索高等动物的新防御系统。该作者等人先前于1986年在大鼠肺中发现了多巴胺-谷胱甘肽或半胱氨酸结合物。从结构上看，这些结合物与Natori的结合物相似，应该是一种内源性的防御物质。第一个目标是合成内源或外源防御物质，以研究其生理作用，如抗菌。在合成过程中，我发现亚硫酸是由半胱氨酸演变而来的。要知道原因，需要它来制造半胱氨酸-S-磺酸。在合成条件下，有聚合物作为副产物，这种聚合被证实参与了甲状腺素运载蛋白通过其半胱氨酸-S-磺酸的淀粉样沉淀。亚硫酸被认为是一种针对防御系统的病原物质。也有人认为，过氧化氢产生的单胺氧化酶从儿茶酚胺发挥了作用。作为一个整体，一个一般的概念被认为是过氧化氢从交感神经系统中的儿茶酚胺使防御与氮氧化物从乙酰胆碱在副交感神经的平衡。

In 1996, Natori et al., found L-Dopa-glutathione conjugate as a novel antibacterial substance in a flesh fly injured. This substance produced hydrogen peroxide to sterilized microorganisms, which suggested a new defense system of insects, In this study, we aimed to explore the new defense system in the higher animals. This author et al. previously identified dopamine-glutathione or cysteine conjugate in the rat lung in 1986. From the structural resemblance to Natori's, these conjugates should be a kind of endogenous defense substances. The first aim was syntheses of endogenous or exogenous defense substances in order to examine their physiological role such as antibacterial. During the synthesis, I found sulfurous acid evolved from cysteine. To know the reason why, it was needed to make cysteins-S-sulfonic acid. There were polymers as by products under the synthetic conditions, This kind of polymerization was confirmed to be involved in amyloid precipitations of transthyretin via its cysteine-S-sulfonic acid. Sulfurous acid was assumed to be an etiological substance against the defense system. It was also assumed that hydrogen peroxide produced from catecholamines by monoamine oxidase played a role. As a whole, a general concept was thought out that hydrogen peroxide from catecholamines in the sympathetic nervous system makes a balance of the defense with nitrogen oxide from acetylcholine in the parasympathetic.