The effects of testosterone on upstream migratory behavior in masu salmon, Oncorhynchus masou.
The effects of testosterone on upstream migratory behavior in masu salmon, Oncorhynchus masou.
复制标题
睾酮对马苏鲑鱼上游洄游行为的影响。
DOI：
10.1006/gcen.2001.7646
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发表时间：
2001
影响因子：
2.7
通讯作者：
K. Aida
中科院分区：
文献类型：
--
作者：
A. Munakata;M. Amano;K. Ikuta;S. Kitamura;K. Aida
利用人工跑道研究了睾酮对大麻哈鱼（Oncorhynchus masou）上游洄游行为的影响。在实验1中，一岁的早熟男性阉割8月植入胶囊的医用硅胶管含有500微克的T在9月。在人工跑道中记录了它们的上游迁移，其中去势和假手术早熟雄性动物植入含有溶剂的胶囊2个月。在实验2中，上游迁移行为的一岁的未成年parr植入胶囊含有T500微克或车辆观察从9月至11月。在实验3中，从9月到10月观察了去势、去势+ T 50 μ g、去势+ T 500 μ g和假手术早熟雄性的上游迁移行为。在实验4中，从9月到10月观察了对照组、T 50 μ g、T 500 μ g和T 1000 μ g处理的未成熟幼仔的上游迁移行为。在每个实验中，从上游移动的鱼中采集血浆和垂体样本，并通过放射免疫测定法测量T，促性腺激素（GTH）II，甲状腺素（T（4））和三碘甲状腺原氨酸（T（3））的水平。T的管理引起血浆T水平在生理范围内的增加。在实验1中，去势组、去势+ T 500 μ g组和假手术组的上游迁移频率分别为0、19.2和35.7%。去势+ T 500 μ g组和假手术组的频率高于去势组。在试验2中，T500微克处理组的频率（22%）高于对照组（2.6%）。在试验1和2中，T处理组和性早熟雄性的垂体GTH Ⅱ含量高于去势性早熟雄性和未成熟幼仔。在实验3中，阉割+ T 50微克，阉割+ T 500微克，和假手术的鱼表现出上游洄游行为，而去势鱼没有T。在实验4中，对照组、T 50 μ g、T 500 μ g和T 1000 μ g处理组的频率分别为5.7%、22.9%、17.1%和28.6%。在每个实验中，迁移者的血浆T（4）水平低于非迁移者，而血浆T（3）水平没有显示出这种变化。从这些结果中，可以推断，T是一个因素，影响上游迁移的马苏鲑鱼。
Effects of testosterone (T) on upstream migratory behavior in masu salmon, Oncorhynchus masou, were studied by use of artificial raceways. In Experiment 1, yearling precocious males castrated in August were implanted with a capsule of medical silicone tube containing 500 microg of T in September. Their upstream migration was recorded in an artificial raceway with castrated and sham-operated precocious males implanted with a capsule containing vehicle for 2 months. In Experiment 2, upstream migratory behavior of yearling immature parr implanted with a capsule containing T 500 microg or vehicle was observed from September through November. In Experiment 3, upstream migratory behavior of castrated, castrated + T 50 microg, castrated + T 500 microg, and sham-operated precocious males was observed from September through October. In Experiment 4, upstream migratory behavior of the control, T 50 microg-, T 500 microg-, and T 1000 microg-treated immature parr was observed from September through October. In each experiment, plasma and pituitary samples were taken from the fish that moved upstream and remained to measure levels of T, gonadotropin (GTH) II, thyroxine (T(4)), and triiodothyronine (T(3)) by radioimmunoassay. Administration of T caused increases in plasma T levels within the physiological range. In Experiment 1, the frequency of migration upstream was 0, 19.2, and 35.7% in the castrated, castrated + T 500 microg, and sham-operated groups, respectively. The frequency was higher in the castrated + T 500 microg and sham-operated groups than in the castrated group. In Experiment 2, the frequency was higher in T 500 microg-treated parr (22%) than in the control (2.6%). In Experiments 1 and 2, pituitary contents of GTH II in the T-treated groups and precocious males were higher than those in the castrated precocious males and immature parr. In Experiment 3, castrated + T 50 microg, castrated + T 500 microg, and sham-operated fish showed upstream migratory behavior, whereas castrated fish without T did not. In Experiment 4, the frequency was 5.7, 22.9, 17.1, and 28.6% in the control, T 50 microg-, T 500 microg-, and T 1000 microg-treated groups, respectively. In each experiment, plasma levels of T(4) in migrants were lower than those in nonmigrants, whereas plasma levels of T(3) did not show such changes. From these results, it is inferred that T is a factor influencing upstream migration in masu salmon.