Low social status impairs hypoxia tolerance in rainbow trout (Oncorhynchus mykiss)
Low social status impairs hypoxia tolerance in rainbow trout (Oncorhynchus mykiss)
复制标题
低社会地位会损害虹鳟鱼（Oncorhynchus mykiss）的缺氧耐受性
DOI：
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
K. Gilmour
中科院分区：
文献类型：
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作者：
J. B. Thomas;K. Gilmour
在本研究中，低社会地位导致的慢性行为应激影响了虹鲑鱼对随后的急性应激源--暴露在低氧中--的生理反应。虹鱼被限制在叉长的配对中48-72h，并根据行为分配社会等级。然后，将优势鱼和次级鱼分别暴露在分级缺氧(最终水PO2，PwO2=40Torr)中。儿茶酚胺的动员谱在优势鱼和从属鱼之间有所不同。在达到特定的释放阈值(PwO2=51.5Torr对应于动脉血氧分压，PaO2=24.1Torr)之前，优势鱼的血浆儿茶酚胺水平普遍较低，而从属鱼类的血浆儿茶酚胺浓度变化较大，确定不同的释放阈值是有问题的。然而，在动化儿茶酚胺的鱼类中(即循环中的儿茶酚胺升至基线附近的95%可信区间以上)，从属鱼类的循环水平(459.9±142.2 nmoL L−1，平均值±扫描电子显微镜，N=12)显著高于优势鱼(130.9±37.9nmoL L−1，N=12)。尽管优势鱼(22.0±1.5Torr，N=6)和从属鱼(22.1±2.2Torr，N=8)的P50值相似，但在严重缺氧条件下(即PwO2和lt；60Torr)，从属鱼的PaO2值较高，但儿茶酚胺的动员存在差异。从属鱼类的PaO2值较高可能反映了这些鱼类在严重缺氧期间表现出的更大的通气率和幅度。在最严重的缺氧条件下，从属鱼类不能防御动脉血中的O2含量，其含量降至优势鱼(1.08±0.09mLO2 g−1血红蛋白，N=9)的一半左右(0.60±0.13mLO2 g−1血红蛋白，N=9)。总而言之，这些数据表明，慢性社会压力影响了鲑鱼对额外的、急性的低氧应激的反应能力。
In the present study, chronic behavioural stress resulting from low social status affected the physiological responses of rainbow trout (Oncorhynchus mykiss) to a subsequent acute stressor, exposure to hypoxia. Rainbow trout were confined in fork-length matched pairs for 48–72 h, and social rank was assigned based on behaviour. Dominant and subordinate fish were then exposed individually to graded hypoxia (final water PO2, PwO2 = 40 Torr). Catecholamine mobilization profiles differed between dominant and subordinate fish. Whereas dominant fish exhibited generally low circulating catecholamine levels until a distinct threshold for release was reached (PwO2 = 51.5 Torr corresponding to arterial PO2, PaO2 = 24.1 Torr), plasma catecholamine concentrations in subordinate fish were more variable and identification of a distinct threshold for release was problematic. Among fish that mobilized catecholamines (i.e. circulating catecholamines rose above the 95% confidence interval around the baseline value), however, the circulating levels achieved in subordinate fish were significantly higher (459.9 ± 142.2 nmol L−1, mean ± SEM, N = 12) than those in dominant fish (130.9 ± 37.9 nmol L−1, N = 12). The differences in catecholamine mobilization occurred despite similar P50 values in dominant (22.0 ± 1.5 Torr, N = 6) and subordinate (22.1 ± 2.2 Torr, N = 8) fish, and higher PaO2 values in subordinate fish under severely hypoxic conditions (i.e. PwO2 < 60 Torr). The higher PaO2 values of subordinate fish likely reflected the greater ventilatory rates and amplitudes exhibited by these fish during severe hypoxia. At the most severe level of hypoxia, subordinate fish were unable to defend arterial blood O2 content, which fell to approximately half (0.60 ± 0.13 mL O2 g−1 haemoglobin, N = 9) that of dominant fish (1.08 ± 0.09 mL O2 g−1 haemoglobin, N = 9). Collectively, these data indicate that chronic social stress impacts the ability of trout to respond to the additional, acute stress of hypoxia.