University of Namur, Unit of Research in Organismal Biology, rue de Bruxelles 61, B-5000 Namur, Belgium.
Fish Shellfish Immunol. 2010 May-Jun;28(5-6):931-41. doi: 10.1016/j.fsi.2010.02.012. Epub 2010 Feb 18.
The effects of acute stress on immune status and its regulation by cortisol/corticosteroid receptors have received little attention in percids. To address that question, we investigated the physiological and immune responses of Eurasian perch, Perca fluviatilis to acute stress. We exposed immature perch to an 1-min exondation and measured at 1 h, 6 h, 24 h and 72 h post-stress: (1) stress-related parameters including plasma cortisol and glucose levels, (2) immune parameters in the plasma and in the spleen (complement, respiratory burst and lysozyme activity, total immunoglobulins; gene expression of lysozyme, complement unit 3, apolipoprotein A1 and 14 kDa, hepcidin and chemotaxin) (3) the corticosteroid receptors gene expression in the spleen after having cloned them. In addition, the in vitro effects of cortisol on the spleen immune parameters were also investigated. Plasma cortisol and glucose levels increased markedly 1h post-stress and returned at basal levels after 24 h. P. fluviatilis mineralocorticoid receptor, but not glucocorticoid receptors, was significantly up-regulated both in vivo after the stress and in vitro by cortisol at a physiological concentration (100 ng/ml). The plasma immune parameters were not significantly affected by the stress. In contrast, spleno-somatic index, spleen lysozyme activity, lysozyme and hepcidin gene expression were depleted and total immunoglobulins increased along the whole time-course (1-72 h). But, these immune parameters were not regulated in vitro by cortisol at physiological or supra-physiological doses. Our results indicate that handling stress may affect spleen antibacterial defences without clear effects on circulating immune compounds and that the elevation of plasma cortisol after handling stress may not be related to the regulation of this splenic response.
急性应激对免疫状态的影响及其通过皮质醇/皮质甾醇受体的调节在鲈形目鱼类中很少受到关注。为了解决这个问题，我们研究了欧亚鲈鱼（Perca fluviatilis）对急性应激的生理和免疫反应。我们将未成熟的鲈鱼暴露于 1 分钟的伸展应激下，并在应激后 1 小时、6 小时、24 小时和 72 小时测量以下参数：（1）应激相关参数，包括血浆皮质醇和葡萄糖水平；（2）血浆和脾脏中的免疫参数（补体、呼吸爆发和溶菌酶活性、总免疫球蛋白；溶菌酶、补体单元 3、载脂蛋白 A1 和 14 kDa、hepcidin 和趋化因子的基因表达）；（3）克隆脾脏中的皮质甾醇受体基因表达。此外，还研究了皮质醇对脾脏免疫参数的体外影响。应激后 1 小时血浆皮质醇和葡萄糖水平显著升高，24 小时后恢复基础水平。P. fluviatilis 盐皮质激素受体，但不是糖皮质激素受体，无论是在体内应激后还是在生理浓度（100ng/ml）的皮质醇体外均显著上调。应激对血浆免疫参数没有显著影响。相反，脾体指数、脾脏溶菌酶活性、溶菌酶和 hepcidin 基因表达减少，总免疫球蛋白在整个时间过程（1-72 小时）中增加。但是，这些免疫参数在生理或超生理剂量的皮质醇体外没有被调节。我们的结果表明，处理应激可能会影响脾脏的抗菌防御能力，而不会对循环免疫化合物产生明显影响，并且处理应激后血浆皮质醇的升高可能与这种脾脏反应的调节无关。
