皮质醇对黄颡鱼成鱼吞噬细胞和补体活性的影响

Effects Cortisol on the Activity of Phagocytes and Complement in Adult Pelteobagrus fulvidraco

采用皮质醇混饲投喂的方法,模拟自然条件下的慢性应激,研究皮质醇对黄颡鱼成鱼吞噬细胞呼吸暴发和血清补体旁路溶血活性(ACH50)的影响。研究结果与结论如下。皮质醇混饲投喂可使血清皮质醇浓度持续显著升高,各周对照组血清皮质醇含量均无显著性差异,证明采用皮质醇混饲投喂的方法可模拟自然慢性应激情况下的血清皮质醇浓度持续显著升高。从第2周开始头肾吞噬细胞的呼吸暴发功能显著下降(P<0.05),证明皮质醇对头肾吞噬细胞的杀菌能力产生显著抑制作用。10mg/kg剂量组,ACH50在投喂第2、第5、第6周显著低于对照组(P<0.05),100mg/kg剂量组,ACH50从第2周开始一直都极显著低于同期对照组(P<0.01),证明皮质醇显著抑制血清补体旁路溶血活性,且血清皮质醇浓度越高其抑制作用越强。

Simulating natural chronic stress,Method of incorporation of cortisol m diet was used to study the effects of cortisol on the phagocyte respiratory burst and the serum alternative complement hemolytic activity （ACH50） of adult yellow catfish （Pelteobagrus fulvidraco ）. The results and conclusions are as follows.The cortisol incorporated in the diet resulted in sustained elevation of serum cortisol concentration, while there was no statistic difference among control groups. This result indicated that the method of incorporation of cortisol in the diet can be used to imitate natural stress response ,which was usually characterized with a continuous increase of the serum cortisol concentration.From the second week,the respiratory burst of the head kidney phagocytes significantly decreased（P〈0.05）. This result indicated that cortisol significandy inhibited the bactericidal ability of the head kidney phagocytes.ACH50 in the 10 mg/kg group decreased significandy（P〈0.05 ）in the second,fifth and sixth weeks, and decreased highly significandy （P〈0.01）in the 100 mg/kg group from the second week to the sixth week. This result indicated that cortisol significantly suppressed the ACH50, and the higher the serum cortisol levels the more pronounced the suppression.