Blank Jason M, Morrissette Jeffery M, Landeira-Fernandez Ana M, Blackwell Susanna B, Williams Thomas D, Block Barbara A
Department of Biological Sciences, Stanford University, Oceanview Boulevard, Pacific Grove, CA 93950, USA.
J Exp Biol. 2004 Feb;207(Pt 5):881-90. doi: 10.1242/jeb.00820.
This study reports the cardiovascular physiology of the Pacific bluefin tuna (Thunnus orientalis) in an in situ heart preparation. The performance of the Pacific bluefin tuna heart was examined at temperatures from 30 degrees C down to 2 degrees C. Heart rates ranged from 156 beats min(-1) at 30 degrees C to 13 beats min(-1) at 2 degrees C. Maximal stroke volumes were 1.1 ml x kg(-1) at 25 degrees C and 1.3 ml x kg(-1) at 2 degrees C. Maximal cardiac outputs were 18.1 ml x kg(-1) min(-1) at 2 degrees C and 106 ml x kg(-1) min(-1) at 25 degrees C. These data indicate that cardiovascular function in the Pacific bluefin tuna exhibits a strong temperature dependence, but cardiac function is retained at temperatures colder than those tolerated by tropical tunas. The Pacific bluefin tuna's cardiac performance in the cold may be a key adaptation supporting the broad thermal niche of the bluefin tuna group in the wild. In situ data from Pacific bluefin are compared to in situ measurements of cardiac performance in yellowfin tuna and preliminary results from albacore tuna.
本研究报告了在原位心脏制备中太平洋蓝鳍金枪鱼（Thunnus orientalis）的心血管生理学。在30℃至2℃的温度范围内检测了太平洋蓝鳍金枪鱼心脏的性能。心率范围从30℃时的156次/分钟到2℃时的13次/分钟。最大搏出量在25℃时为1.1 ml·kg⁻¹，在2℃时为1.3 ml·kg⁻¹。最大心输出量在2℃时为18.1 ml·kg⁻¹·min⁻¹，在25℃时为106 ml·kg⁻¹·min⁻¹。这些数据表明，太平洋蓝鳍金枪鱼的心血管功能表现出强烈的温度依赖性，但在比热带金枪鱼所能耐受的温度更低的情况下仍能保持心脏功能。太平洋蓝鳍金枪鱼在寒冷环境中的心脏性能可能是支持蓝鳍金枪鱼群体在野外广泛热生态位的关键适应性特征。将太平洋蓝鳍金枪鱼的原位数据与黄鳍金枪鱼心脏性能的原位测量数据以及长鳍金枪鱼的初步结果进行了比较。
