Developmental and Integrative Biology Division, Department of Biological Sciences, University of North Texas, Denton, TX 76203, USA.
Developmental and Integrative Biology Division, Department of Biological Sciences, University of North Texas, Denton, TX 76203, USA
J Exp Biol. 2019 Aug 16;222(Pt 16):jeb205211. doi: 10.1242/jeb.205211.
Blood flow patterns and heart rate have rarely been investigated in freely swimming turtles and their regulation during swimming is unknown. In this study, we investigated the blood flow patterns and heart rate in surfacing and during graded, submerged swimming activity in common snapping turtles. We further investigated the effects of beta-adrenergic and cholinergic receptor blockade on blood flow and heart rate during these activities. Our findings illustrate that surfacing is accompanied by an increase in heart rate that is primarily due to beta-adrenergic stimulation. During swimming, this mechanism also increases heart rate while vagal withdrawal facilitates a systemic to pulmonary (left to right) shunt. The results indicate there may be important taxonomic effects on the responses of cardiac function to activity in turtle species.
血流模式和心率在自由游泳的海龟中很少被研究，它们在游泳过程中的调节也不清楚。在这项研究中，我们研究了普通 snapping 龟在浮出水面和分级、潜水游泳活动中的血流模式和心率。我们还研究了β-肾上腺素能和胆碱能受体阻断对这些活动中血流和心率的影响。我们的研究结果表明，浮出水面伴随着心率的增加，这主要是由于β-肾上腺素能的刺激。在游泳过程中，这种机制也会增加心率，同时迷走神经的撤出促进了体循环到肺循环（从左到右）的分流。结果表明，在龟类物种的心脏功能对活动的反应中，可能存在重要的分类学效应。
