Gieseg S P, Reibnegger G, Wachter H, Esterbauer H
Institute für Biochemie, Universität Graz, Austria.
Free Radic Res. 1995 Aug;23(2):123-36. doi: 10.3109/10715769509064027.
Neopterin and its reduced form, 7,8 dihydroneopterin are pteridines released from macrophages and monocytes when stimulated with interferon gamma in vivo. The function of this response is unknown though there is an enormous amount of information available on the use of these compounds as clinical markers of monocyte/macrophage activation. We have found that in vitro 7,8-dihydroneopterin dramatically increases, in a dose dependent manner, the lag time of low density lipoprotein oxidation mediated by Cu++ ions or the peroxyl radical generator 2,2'-azobis (2-amidino propane) dihydrochloride (AAPH). 7,8-Dihydroneopterin also inhibits AAPH mediated oxidation of linoleate. The kinetic of the inhibition suggests that 7,8-dihydroneopterin is a potent chain breaking antioxidant which functions by scavenging lipid peroxyl radicals. No anti-oxidant activity was observed in any of the oxidation systems studied with the related compounds neopterin and pterin.
新蝶呤及其还原形式7,8-二氢新蝶呤是体内巨噬细胞和单核细胞在γ干扰素刺激下释放的蝶啶。尽管关于这些化合物作为单核细胞/巨噬细胞激活的临床标志物的应用已有大量信息，但这种反应的功能尚不清楚。我们发现，在体外，7,8-二氢新蝶呤以剂量依赖性方式显著增加由铜离子或过氧自由基发生器2,2'-偶氮双（2-脒基丙烷）二盐酸盐（AAPH）介导的低密度脂蛋白氧化的延迟时间。7,8-二氢新蝶呤还抑制AAPH介导的亚油酸氧化。抑制动力学表明，7,8-二氢新蝶呤是一种有效的链断裂抗氧化剂，其作用是清除脂质过氧自由基。在用相关化合物新蝶呤和蝶呤研究的任何氧化系统中均未观察到抗氧化活性。
