Findsen Anders, Crossley Dane A, Wang Tobias
Zoophysiology, Department of Biosciences, Aarhus University, Aarhus, Denmark; Department of Biological Sciences, University of North Texas, Denton, TX, USA.
Department of Biological Sciences, University of North Texas, Denton, TX, USA.
Comp Biochem Physiol A Mol Integr Physiol. 2018 Jan;215:1-5. doi: 10.1016/j.cbpa.2017.09.001. Epub 2017 Sep 27.
The crocodilian cardiovascular design with a four-chambered heart and a left aorta that emerge from the right ventricle allows blood to be shunted away from the lungs, a right-to-left (R-L) shunt. The adaptive significance of this R-L shunt remains both poorly understood and controversial with particular debate on its putative role during digestion. Here we measure blood flow patterns in the right aorta (RAo), left aorta (LAo) and the coeliac artery (CoA) of undisturbed American alligators (Alligator mississippiensis) during fasting and throughout most of the digestive period. Digestion doubled blood flow in the RAo (10.1±0.9 to 20.7±1.5mlminkg), whereas LAo increased approximately 3-fold (3.8±0.6 to 12.2±2.1mlminkg). Blood flow in the CoA increased more than four-fold during digestion (3.0±0.6 to 13.3±1.6mlminkg). The rise in blood flows was achieved by a doubling of heart rate (18.5±3.3 to 37.8±3.6mlminkg). Maximal flows measured in all arteries and heart rate occurred in the first hour of the postprandial period and continued for the next 7h.
鳄鱼的心血管系统设计包括一个四腔心脏和一条从右心室发出的左主动脉，这使得血液能够从肺部分流，即右向左（R-L）分流。这种R-L分流的适应性意义仍然知之甚少且存在争议，尤其是关于其在消化过程中假定作用的争论。在这里，我们测量了禁食期间以及整个消化期大部分时间里，未受干扰的美国短吻鳄（密西西比鳄）的右主动脉（RAo）、左主动脉（LAo）和腹腔动脉（CoA）中的血流模式。消化过程中，RAo的血流量增加了一倍（从10.1±0.9增加到20.7±1.5毫升/分钟·千克），而LAo增加了约3倍（从3.8±0.6增加到12.2±2.1毫升/分钟·千克）。消化期间CoA的血流量增加了四倍多（从3.0±0.6增加到13.3±1.6毫升/分钟·千克）。血流量的增加是通过心率加倍实现的（从18.5±3.3增加到37.8±3.6次/分钟）。所有动脉中测量到的最大血流量和心率出现在餐后的第一个小时，并持续接下来的7小时。
