Trenzado C E, Carrick T R, Pottinger T G
Departamento de Biología Animal y Ecología, Facultad de Ciencias, Universidad de Granada, Campus Fuentenueva s/n, 18071 Granada, Spain.
Gen Comp Endocrinol. 2003 Oct 1;133(3):332-40. doi: 10.1016/s0016-6480(03)00191-6.
Rainbow trout (Oncorhynchus mykiss) of two lines selected for low (LR) and high (HR) cortisol stress-responsiveness were subjected to confinement for a period of 336 h. Endocrine (plasma cortisol, hepatic cortisol binding) and metabolic (plasma glucose, lactate, amino acids; hepatic glycogen and alanine aminotransferase levels) indices of stress were measured at intervals in confined and unconfined fish of both lines. During confinement plasma cortisol concentration reached maximum values earlier in HR fish (2h) than in LR fish (6h) returning to control values within 336 h in both lines. Paradoxically, although both HR and LR lines displayed a characteristic metabolic stress response, these changes were more pronounced in LR fish. Plasma glucose and lactate levels increased during confinement in both lines but to a significantly greater extent in LR fish. Confinement significantly elevated plasma amino acids to a greater extent in LR fish than in HR fish. Liver glycogen concentration was depleted most rapidly in LR fish but was significantly higher in confined fish of both lines than controls at the end of the experiment. No significant changes were observed in hepatic alanine aminotransferase activity during confinement. Confined fish of both lines displayed a decrease in hepatic cortisol receptor abundance within 24h and this was more sustained in HR fish. The more pronounced disturbance of a broad range of indicators of stress in confined LR fish, compared to HR fish, throws doubt on the magnitude of the cortisol response being the primary driver of these differences.
选取了对皮质醇应激反应较低（LR）和较高（HR）的两个品系的虹鳟（Oncorhynchus mykiss），将它们置于限制环境中336小时。在限制环境中和未限制环境中，对两个品系的虹鳟鱼定期测量应激的内分泌指标（血浆皮质醇、肝脏皮质醇结合能力）和代谢指标（血浆葡萄糖、乳酸、氨基酸；肝脏糖原和丙氨酸转氨酶水平）。在限制环境中，HR品系的鱼血浆皮质醇浓度在2小时时达到最大值，早于LR品系的鱼（6小时），并且在336小时内两个品系的鱼血浆皮质醇浓度均恢复到对照值。矛盾的是，尽管HR和LR品系都表现出典型的代谢应激反应，但这些变化在LR品系的鱼中更为明显。两个品系的鱼在限制环境中血浆葡萄糖和乳酸水平均升高，但LR品系的鱼升高幅度更大。限制环境使LR品系的鱼血浆氨基酸升高的程度明显大于HR品系的鱼。LR品系的鱼肝脏糖原浓度消耗最快，但在实验结束时，两个品系处于限制环境中的鱼肝脏糖原浓度均显著高于对照鱼。在限制环境中，肝脏丙氨酸转氨酶活性未观察到显著变化。两个品系处于限制环境中的鱼在24小时内肝脏皮质醇受体丰度均下降，且HR品系的鱼下降更持久。与HR品系的鱼相比，限制环境中的LR品系的鱼多种应激指标受到更明显的干扰，这使人怀疑皮质醇反应的程度是否是造成这些差异的主要驱动因素。
