Abstract

Redox reactions accompanied by the oxidation–reduction of endogenous molecules play important roles in maintaining homeostasis in living organisms. In humans, numerous endogenous molecules that contribute towards maintaining physiological conditions form free radicals via electron transfer. A typical example of this is the mitochondrial electron transport chain, which is involved in energy production. If free radicals derived from endogenous molecules could be visualised and exploited as biological and functional probes, redox reactions mediated by endogenous molecules could be detected non-invasively. We succeeded in visualising the free radicals derived from endogenous molecules using an in vivo dynamic nuclear polarisation (DNP) magnetic resonance imaging (MRI) system. In this review, we describe the visualisation of endogenous redox molecules, such as flavins and ubiquinones, which are mitochondrial electron carriers, as well as vitamin E and vitamin C (ascorbate). In addition, we describe the application of melanin free radicals for the in vivo visualisation of metabola without using probes via in vivo DNP-MRI.

摘要

伴随着内源性分子的氧化还原的氧化还原反应在维持生物体内的稳态中起重要作用。在人类中，许多有助于维持生理条件的内源性分子通过电子转移形成自由基。一个典型的例子是线粒体电子传递链，它参与能量生产。如果可以将源自内源性分子的自由基可视化并用作生物和功能性探针，则可以无创地检测由内源性分子介导的氧化还原反应。我们成功地使用体内观察了源自内源性分子的自由基动态核极化（DNP）磁共振成像（MRI）系统。在这篇综述中，我们描述了内源性氧化还原分子的可视化，例如黄素和泛醌，它们是线粒体电子载体，以及维生素 E 和维生素 C（抗坏血酸）。此外，我们通过体内DNP-MRI描述了在不使用探针的情况下使用黑色素自由基在体内可视化代谢物的应用。