Sexual maturity modifies the responsiveness of the pituitary-interrenal axis to stress in male rainbow trout.
Sexual maturity modifies the responsiveness of the pituitary-interrenal axis to stress in male rainbow trout.
复制标题
性成熟改变了雄性虹鳟鱼垂体-肾间轴对压力的反应能力。
DOI：
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发表时间：
1995
影响因子：
2.7
通讯作者：
A. D. Pickering
中科院分区：
文献类型：
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作者：
T. Pottinger;P. Balm;A. D. Pickering
应激诱导的血浆皮质醇水平显着降低是明显的成熟雄性虹鳟鱼相比，不成熟的鱼的性别和相同的年龄和应变。平均血浆皮质醇水平组未成熟的鱼受到一个标准的1小时禁闭压力一贯较高（范围：93.9 +/- 4.9-114.8 +/- 4.1 ng ml-1）高于暴露于相同程序的成年雄性的平均水平（范围47.0 +/- 4.3-71.7 +/- 5.7 ng ml-1），在整个产卵前后的4个月期间（P < 0.001）。体重没有被发现是一个显着的决定因素后应激皮质醇水平。成熟和未成熟的鱼之间血浆皮质醇水平的差异，以下禁闭并不源于不同的动态反应;在24小时的禁闭期间，成熟雄性鱼和未成熟鱼的血浆皮质醇水平的升高速率相似，但成熟的雄鱼达到了显着较低的峰值皮质醇水平，（51.6 +/- 5.2 ng ml-1）比未成熟的鱼（89.5 +/- 7.7 ng ml-1），在整个应激期间保持这种差异（P < 0.05-P < 0.001）。成熟雄鱼肾间组织在应激过程中的反应性降低似乎是由下丘脑/垂体调节的。成熟雄性鳟鱼的血浆ACTH水平（44 +/- 9 pg ml-1）在禁闭开始的30分钟内显著低于未成熟鱼的血浆ACTH水平（71 +/- 9 pg ml-1，P < 0.01），并且在禁闭的3小时期间保持如此。这些数据表明，皮质醇/促肾上腺皮质激素反馈平衡已被修改，在成熟的鱼到一个较低的“设定点。“此外，虽然压力导致血浆α-MSH水平显着下降，在未成熟的鱼和成熟的男性，N-乙酰-β-内啡肽水平下降，只有在成熟的雄鱼在禁闭压力。
A significant reduction in stress-induced plasma cortisol levels is apparent in mature male rainbow trout compared to immature fish of both sexes and of the same age and strain. Mean plasma cortisol levels in groups of immature fish subjected to a standard 1-hr confinement stress were consistently higher (range 93.9 +/- 4.9-114.8 +/- 4.1 ng ml-1) than mean levels in mature males exposed to the same procedure (range 47.0 +/- 4.3-71.7 +/- 5.7 ng ml-1), throughout the 4-month period around spawning (P < 0.001). Body weight was not found to be a significant determinant of poststress cortisol level. The dissimilarity in plasma cortisol levels between mature and immature fish following confinement does not stem from differences in the dynamics of the response; during a 24-hr period of confinement the rate of elevation of plasma cortisol levels was similar for both mature male and immature fish, but mature male fish attained a significantly lower peak cortisol level (51.6 +/- 5.2 ng ml-1) than immature fish (89.5 +/- 7.7 ng ml-1), a disparity which was maintained throughout the period of stress (P < 0.05-P < 0.001). The reduced responsiveness of the interrenal tissue of mature male fish during stress appears to be modulated by the hypothalamus/pituitary. Plasma ACTH levels in mature male trout (44 +/- 9 pg ml-1) are significantly lower than those in immature fish (71 +/- 9 pg ml-1, P < 0.01) within 30 min of the onset of confinement and remain so during a 3-hr period of confinement. These data suggest that the cortisol/ACTH feedback equilibrium has been modified in mature fish to a lower "set point." Furthermore, although stress caused a significant decline of plasma alpha-MSH levels in both immature fish and mature males, N-acetyl-beta-endorphin levels were reduced only in mature male fish during confinement stress.