β-胡萝卜素在100%氧气压力下于大鼠肝微粒体中的促氧化活性。

Prooxidant activity of beta-carotene under 100% oxygen pressure in rat liver microsomes.

作者信息

Palozza P, Calviello G, Bartoli G M

机构信息

Institute of General Pathology, Catholic University, Rome, Italy.

出版信息

Free Radic Biol Med. 1995 Dec;19(6):887-92. doi: 10.1016/0891-5849(95)00094-e.

DOI:10.1016/0891-5849(95)00094-e

PMID:8582664

Abstract

The effects of the partial pressure of oxygen (pO2) on antioxidant efficiency of beta-carotene in inhibiting 2,2'-azobis(2-amindinopropane) (AAPH)-induced lipid peroxidation are investigated in rat liver microsomal membranes. The rate of peroxyl radicals generated by thermolysis of AAPH at 37 degrees C is markedly higher at 150 than 760 mm Hg pO2. At 150 mm Hg Po2 beta-carotene acts as an antioxidant, inhibiting 2,2'-azobis(2-amidinopropane) 9AAPH0-induced Malonidaldehyde (MDA) formation. At 760 mm Hg Po2, it loses its antioxidant activity and shows a prooxidant effect, increasing lipid peroxidation products. alpha-Tocopherol prevents the prooxidant effect of beta-carotene in a dose-dependent manner. Our data provide the first evidence of a prooxidant effect of beta-carotene under 100% oxygen pressure in a biological membrane model and point out the existence of cooperative interactions between beta-carotene and alpha-tocopherol.

摘要

在大鼠肝微粒体膜中研究了氧分压（pO₂）对β-胡萝卜素抑制2,2'-偶氮二异丁腈（AAPH）诱导的脂质过氧化的抗氧化效率的影响。在37℃下，AAPH热解产生过氧自由基的速率在150 mmHg pO₂时明显高于760 mmHg pO₂时。在150 mmHg pO₂时，β-胡萝卜素作为抗氧化剂，抑制2,2'-偶氮二异丁脒（AAPH）诱导的丙二醛（MDA）形成。在760 mmHg pO₂时，它失去抗氧化活性并表现出促氧化作用，增加脂质过氧化产物。α-生育酚以剂量依赖的方式防止β-胡萝卜素的促氧化作用。我们的数据首次证明了在生物膜模型中100%氧气压力下β-胡萝卜素的促氧化作用，并指出了β-胡萝卜素与α-生育酚之间存在协同相互作用。