The effects of acute changes in temperature and oxygen availability on cardiac performance in winter flounder (Pseudopleuronectes americanus)
The effects of acute changes in temperature and oxygen availability on cardiac performance in winter flounder (Pseudopleuronectes americanus)
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DOI：
10.1016/j.cbpa.2009.11.006
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发表时间：
2010-02-01
影响因子：
2.3
通讯作者：
Gamperl, A. Kurt
中科院分区：
文献类型：
--
作者：
Mendonca, Paula C.;Gamperl, A. Kurt
关于比目鱼心血管功能如何响应环境挑战的研究有限，主要依赖间接方法(即Fick原理)。因此，我们测量了8摄氏度和15摄氏度驯化的比目鱼暴露在分级低氧下的背主动脉血压(P-DA)和心功能，以及8摄氏度驯化的鱼暴露在急性升温到临界温度最大值(CTM)时的背主动脉血压(P-DA)和心功能。在8摄氏度驯化的鱼中，心跳缓慢的程度(心率下降41%)与其他硬骨鱼的观察结果一致，该物种的CTM(25.8+/-0.5摄氏度)及其对温度升高的心脏反应也是如此。然而，这项研究提供了进一步的例子，说明与其他鱼类相比，比目鱼的心血管功能是如何受到不同的控制的。首先，在8摄氏度驯化的鱼中，这种不活跃和耐缺氧的物种(60%的水-气饱和度)比预期的心动过缓发生得更早。其次，在8℃和15℃下习服的比目鱼的静息心输出量相似(类似于15mLmin(-1)kg(-1))，在15℃时出人意料地没有缺氧性心动过缓，当比目鱼暴露在高温下时，全身血管阻力下降，导致P-DA下降26%。这些都是新的发现，然而，比目鱼的行为对一些结果的影响程度尚不清楚。(C)2009 Elsevier Inc.保留所有权利。
Studies on how flatfish cardiovascular function responds to environmental challenges are limited, and have largely relied upon indirect methodologies (i.e. Fick principle). Thus, we measured dorsal aortic blood pressure (P-DA) and cardiac function in 8 and 15 degrees C-acclimated flounder exposed to graded hypoxia, and in 8 degrees C-acclimated fish exposed to an acute temperature increase to their critical thermal maximum (CTM). The extent of bradycardia in 8 degrees C-acclimated fish (decrease in heart rate of 41%) was consistent with that observed for other teleosts, as was this species' CTM (25.8 +/- 0.5 degrees C) and its cardiac response to increasing temperature. However, this study provides further examples of how cardiovascular function is controlled differently in the flounder as compared with other fishes. First, the onset of bradycardia in 8 degrees C-acclimated fish occurred earlier than expected for this inactive and hypoxia-tolerant species (60% water air saturation). Second, resting cardiac output was similar in flounder acclimated to 8 and 15 degrees C (similar to 15 mL min(-1) kg(-1)), and hypoxic bradycardia was surprisingly absent at 15 degrees C Finally, systemic vascular resistance decreased when flounder were exposed to elevated temperature, and this resulted in a 26% fall in P-DA. These are novel findings, however, the extent to which the flounder's behaviour influenced some of the results is unclear. (C) 2009 Elsevier Inc. All rights reserved.