干旱胁迫对大鳞副泥鳅免疫指标的影响

Effects of drought stress on immune response Paramisgurnus dabryanus

为探究气呼吸型鱼类在养殖运输中常遭遇的短时干旱胁迫对其免疫应答的影响,本实验以大鳞副泥鳅(Paramisgurnus dabryanus)为研究对象,将其暴露于空气中12、24、48、72、96 h后检测血清和肝脏免疫指标的变化。结果显示:空气暴露显著增加了大鳞副泥鳅血清总蛋白、白蛋白、球蛋白和免疫球蛋白M含量,但对血清和肝脏溶菌酶活性无显著影响。补体C3和补体C4含量均呈先升后降的变化趋势。血清热休克蛋白70和热休克蛋白90含量在暴露48 h分别升高至基础水平的3.3倍和2.0倍。血清炎症细胞因子水平随着暴露时间的延长呈现先升后降的趋势;空气暴露12 h,肝脏肿瘤坏死因子-α和白细胞介素-1β上升至基础水平的1.4倍,白细胞介素-6和白细胞介素-12上升至1.5倍。上升的免疫指标表明短期(0~48 h)的干旱胁迫对大鳞副泥鳅有明显的免疫刺激作用,随后多数免疫指标在实验后期(48~96 h)下降,表明持续的干旱胁迫导致免疫刺激转为免疫抑制作用。

In this experiment,the Paramisgurnus dabryanus was used as a model to examine the impact of short-term drought stress on the immune response of air-breathing fish that are frequently encountered in aquaculture and transportation.After 12,24,48,72,and 96 hours of air exposure,alterations in the serum and liver immunological indices were detected.According to the results,exposure to air considerably increased serum levels of total protein,albumin,globulin,and immunoglobulin M(IgM).However,there was no discernible impact on serum or liver lysozyme activity.Complement C3 and C4 levels in serum and liver showed a trend of increasing and subsequently lowering levels.At 48 hours after exposure,serum levels of heat shock proteins 70(HSP70)and 90(HSP90)increased to 3.3 and 2.0-flod of basal levels,respectively.Liver HSP70 and HSP90 levels peaked at 12 hours after exposure and subsequently dropped quickly to basal levels.After 12 h of air exposure,the TNF-αand IL-1βin liver increased to 1.4-fold of basal level,and the contents of IL-6 and IL-12 increased to 1.5-fold of basal level.In conclusion,the response of liver immune factors was more rapid and significantly upregulated at the early stage of air exposure,while the serum indexes were more lasting.The rising immune indexes indicated that short-term(0~48 h)drought stress significantly stimulated P.dabryanus.Then most of the immune indexes declined at the later stage of the experiment(48~96 h),indicating that persistent drought stress led to immune stimulation into immunosuppression.The experimental findings offer fundamental knowledge for transporting anhydrous fish and boosting fish immune and illness resistance.