黄曲霉毒素对大鼠肝脏线粒体氧化磷酸化的影响。

Effect of aflatoxins on oxidative phosphorylation by rat liver mitochondria.

作者信息

Ramachandra Pai M, Jayanthi Bai N, Venkitasubramanian T A

出版信息

Chem Biol Interact. 1975 Feb;10(2):123-31. doi: 10.1016/0009-2797(75)90106-4.

Abstract

The in vitro effect of aflatoxins M1, B1 and G1 on oxidative phosphorylation by rat liver mitochondria with succinate as substrate has been studied. All these toxins inhibit the electron transport chain at a 1-10-4 M concentration and the site of inhibition is between cytochrome b and cytochrome c or c1. Aflatoxin M1 (AFM1) uncouples oxidative phosphorylation at a concentration of 1-10-6 M and reduces the ADP:O ratio, whereas aflatoxin B1 (AFB1) at 1-10-6 M concentration uncouples oxidative phosphorulation but does not affect the ADP:O ratio. At a concentration of 1-10-5 M, AFB1 also decreases the ADP:O ratio along with the uncoupling of oxidative phosphorylation. Aflatoxin G1 (AFG1) acts as an uncoupler at a relatively higher concentration of 1-10-4 M. Preincubation of mitochondria with these aflatoxins resulted in inhibition of respiration and uncoupling of rat liver mitochondria.

摘要

研究了黄曲霉毒素M1、B1和G1在以琥珀酸为底物时对大鼠肝线粒体氧化磷酸化的体外作用。所有这些毒素在1×10⁻⁴ M浓度时抑制电子传递链，抑制位点在细胞色素b与细胞色素c或c1之间。黄曲霉毒素M1（AFM1）在1×10⁻⁶ M浓度时使氧化磷酸化解偶联并降低ADP:O比值，而黄曲霉毒素B1（AFB1）在1×10⁻⁶ M浓度时使氧化磷酸化解偶联但不影响ADP:O比值。在1×10⁻⁵ M浓度时，AFB1在使氧化磷酸化解偶联的同时也降低ADP:O比值。黄曲霉毒素G1（AFG1）在相对较高的1×10⁻⁴ M浓度时起解偶联剂的作用。用这些黄曲霉毒素对线粒体进行预孵育会导致大鼠肝线粒体呼吸抑制和解偶联。