高铜日粮对肉鸡肝细胞线粒体呼吸链复合物活性的影响

Effect of high-copper diet on activities of respiratory chain complexes in liver mitochondria of broilers

在对照组(Cu 11 mg/kg,A组)基础上设高铜组3个(110 mg/kg、220 mg/kg和330 mg/kg,分别对应为试验组B、C、D),试验期为60 d,在12、24、36、48、60日龄采集肝组织,提取线粒体,测定线粒体复合物Ⅰ、Ⅱ、Ⅲ、Ⅳ和Ⅴ的活性变化。结果表明,11 mg/kg和110 mg/kg铜日粮添加组线粒体复合物Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ的活性呈增加趋势。220 mg/kg和330 mg/kg铜日粮添加组肉鸡肝细胞线粒体复合物Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ活性减弱,但主要在试验后期,尤其是48日龄之后,比对照组和各组内的试验前期下降明显(P<0.05)。说明高铜日粮在一定程度上对线粒体复合物活性是有利的,但过高的铜添加到日粮中(≥220 mg/kg)可降低肉鸡肝细胞线粒体呼吸链复合物的功能活性。据此可以推测,线粒体是机体铜过量状态下侵害的靶部位之一,而且能作用于线粒体各个复合物,造成线粒体呼吸功能减弱,呼吸链中电子传递发生故障,从而影响线粒体功能的正常发挥。

In addition to the control group（Cu 11 mg/kg,Group A）, three experimental groups were set up,they were Groups 110 mg/kg（Group B） ,220 mg/kg（Group C） and 330 mg/kg（Group D） respectively. All of the experimental broilers were fed with corn-soybean meal for 60 days, and the activities of mitochondrial complex from broilers＂ hepatocyte were assayed on 12,24,36,48 and 60 day-old. The high-copper diet had influence on liver mitochondrial complex, the activities of each complex in Groups A and B had a tendency of increasing, more obviously in Group B（P〈0.05）, hut were subject to decrease in Group C and D（P〈0.05）, especially on the later stage of whole experiment（after 48 day-old）, which indicated that highcopper diet could he helpful to liver mitochondrial complex of broiler to some extent, hut too high-copper diet （≥220 mg/kg） might degrade activity of them. It was presumed that mitochondria was the invasive target under the condition of copper excess, and this effect was mainly on mitochondrial complex which resulted in decreasing of respiratory function and breakdown of electron transfer, then made seriously mitochondrial electron transport chain broke down, which may he was one of the essential reasons of copper toxicity to living organism.