Biemond P, Swaak A J, Beindorff C M, Koster J F
Biochem J. 1986 Oct 1;239(1):169-73. doi: 10.1042/bj2390169.
Xanthine oxidase is able to mobilize iron from ferritin. This mobilization can be blocked by 70% by superoxide dismutase, indicating that part of its action is mediated by superoxide (O2-). Uric acid induced the release of ferritin iron at concentrations normally found in serum. The O2(-)-independent mobilization of ferritin iron by xanthine oxidase cannot be attributed to uric acid, because uricase did not influence the O2(-)-independent part and acetaldehyde, a substrate for xanthine oxidase, also revealed an O2(-)-independent part, although no uric acid was produced. Presumably the amount of uric acid produced by xanthine oxidase and xanthine is insufficient to release a measurable amount of iron from ferritin. The liberation of iron from ferritin by xanthine oxidase has important consequences in ischaemia and inflammation. In these circumstances xanthine oxidase, formed from xanthine dehydrogenase, will stimulate the formation of a non-protein-bound iron pool, and the O2(-)-produced by xanthine oxidase, or granulocytes, will be converted by 'free' iron into much more highly toxic oxygen species such as hydroxyl radicals (OH.), exacerbating the tissue damage.
黄嘌呤氧化酶能够从铁蛋白中动员铁。这种动员作用可被超氧化物歧化酶阻断70%，这表明其部分作用是由超氧化物（O2-）介导的。尿酸在血清中通常存在的浓度下可诱导铁蛋白铁的释放。黄嘌呤氧化酶对铁蛋白铁的非O2-依赖性动员作用不能归因于尿酸，因为尿酸酶不影响非O2-依赖性部分，并且乙醛作为黄嘌呤氧化酶的一种底物，也显示出非O2-依赖性部分，尽管没有产生尿酸。推测黄嘌呤氧化酶和黄嘌呤产生的尿酸量不足以从铁蛋白中释放出可测量的铁量。黄嘌呤氧化酶使铁蛋白释放铁在缺血和炎症中具有重要影响。在这些情况下，由黄嘌呤脱氢酶形成的黄嘌呤氧化酶会刺激形成一个非蛋白结合铁池，并且黄嘌呤氧化酶或粒细胞产生的O2-会被“游离”铁转化为毒性更强的氧物种，如羟基自由基（OH·），从而加剧组织损伤。
