环境胁迫对鱼类免疫系统影响的研究概况

The effect of environmental stress to fish immune system

环境胁迫(environmental stress)是指环境对鱼类所处的生存状态产生的压力,可以分为急性环境胁迫和慢性环境胁迫.捉捞(handling)和干扰(disturbance)等引起急性环境胁迫,而水质逐渐恶化和高密度放养等造成慢性胁迫[1].随着世界人口的增长和消费水平的提高,世界渔业也得到了长足的发展.但与此同时,由于人类活动范围的扩大、程度的加深,环境资源受到了很大的破坏,环境对鱼类引起的胁迫也日益严重.

Environmental stress can increase the plasma cortisol level of fish and long - term elevation of this hormone in plasma would inhibit immune function, hurt immune organs, increase the susceptibility of fish to pathogens. The numbers of fish lymphocytes decrease after cortisol administration. But when neutrophils, macrophages, non-specific cytotoxic cells, antibody-producing cells and plague-forming cells are concerned, the stress or cortisol administration may activate or restrain their activities. Humoral immune factors, such as lysozyme and complement of fish, are often suppressed by environmental stress. When fish encounter stress, some parts of immune system of fish may be suppressed immunologically, while the others boosted up as compensation to overcome the stress.