冬眠哺乳动物氧化应激产生及抗氧化防御机制研究进展

哺乳动物的冬眠是一种季节性异温状态,是对外界恶劣自然环境的一种适应策略。冬眠-阵间觉醒周期中,伴随着生理功能的剧烈变化,从冬眠期间整体代谢的抑制,到阵间觉醒时氧代谢的急剧增加,使动物体内产生了大量的氧自由基。然而,冬眠动物出眠时并未表现出明显的氧化损伤迹象,因此,冬眠哺乳动物被认为是一种天然的抗氧化损伤模型。本文从氧化应激的产生、活性氧的来源、抗氧化防御等方面综述了冬眠哺乳动物对氧化应激的防御,并从其抗氧化的分子调控方面分析了冬眠哺乳动物对氧化应激的适应机制。

Oxidative Stress and Mechanism of Antioxidant Defense in Hibernating Mammals

Mammalian hibernation is a state of seasonal heterothermy and survival strategy. The hibernation consists of long periods of deep torpor interspersed by brief interbout arousal periods. During torpor, metabolic rate is profoundly depressed and core body temperature decreases to near ambient temperature. However, these functions are promptly restored to the basic level upon arousal, and a quick restoration of blood flow accompanied by an increased mitochondrial respiration and oxygen usage results in elevated generation of reactive oxygen species (ROS) in mammals. However, no oxidative damage is found in the tissues of hibernators during a prolonged period of hibernation. Small mammalian hibernators have, therefore, been considered to be the best model of the anti-oxidative damage. In this paper, the adaptation mechanisms of oxidative stress to hibernating mammals are reviewed with respect to the generation of oxidative stress, the source of ROS and antioxidant defense.