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首页> 外文期刊>American Journal of Physiology >Body, eye, and chorioallantoic vessel growth are not dependent on cardiac output level in day 3-4 chicken embryos.
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Body, eye, and chorioallantoic vessel growth are not dependent on cardiac output level in day 3-4 chicken embryos.

机译：身体，眼睛和绒囊尿道血管的生长不依赖于第3-4天鸡胚的心输出量水平。

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Normal aerobic metabolic rates persist in the early chicken embryo after elimination of cardiac output, but the dependence of tissue growth and differentiation on blood flow is unknown in these early stages. We partially ligated (25-50% occlusion) the ventricular outflow tract of Hamburger-Hamilton stage (HH) 16-18 embryos, producing a wide range of cardiac output. For the next approximately 48 h (to HH 24), we measured heart rate (HR), stroke volume (SV), and cardiac output (CO), as well as these growth indicators: eye diameter, chorioallantoic vessel density, and body mass. Acutely, HR declined with partial ligation (from 108 to 98 beats/min). Paradoxically, SV and CO decreased sharply in most embryos but increased in others, collectively producing the desired large variation (up to 25-fold) in CO and permitting assessment of tissue growth over a very large range of blood perfusion. Eye diameter doubled (from 0.6 to 1.2 mm) with development from HH 16 to HH 24, but within a developmental cohort therewas no significant correlation between eye diameter and CO over a 25-fold range of CO. Similarly, chorioallantoic membrane vessel index was independent of CO over the CO range at all stages. Finally, body mass increase during development was not significantly affected by partial conal truncal ligation. Collectively, these data suggest that normal eye and vessel growth and body mass accumulation occur independent of their rate of blood perfusion, supporting the hypothesis of prosynchronotropy-that the heart begins to beat and generate blood flow in advance of the actual need for convective blood flow to tissues.
机译：在消除心排血后，早期鸡胚中仍保持正常的有氧代谢率，但是在这些早期阶段，组织生长和分化对血流的依赖性尚不清楚。我们部分结扎（25-50％阻塞）Hamburger-Hamilton阶段（HH）16-18胚胎的心室流出道，产生广泛的心输出量。在接下来的大约48小时（至HH 24）中，我们测量了心率（HR），中风量（SV）和心输出量（CO），以及以下生长指标：眼睛直径，绒膜尿道血管密度和体重。急性时，HR随部分结扎而下降（从108次/分降至98次/分）。矛盾的是，大多数胚胎中的SV和CO急剧下降，而其他胚胎中的SV和CO急剧上升，共同在CO中产生所需的大变化（最多25倍），并允许在很大范围的血液灌注中评估组织的生长。从HH 16到HH 24的发育，眼睛直径增加了一倍（从0.6到1.2 mm），但是在发育队列中，在CO的25倍范围内，眼睛直径和CO之间没有显着相关性。类似地，绒膜尿囊膜血管指数是独立的在所有阶段的CO超出CO范围。最后，部分圆锥形截尾结扎术并未显着影响发育过程中的体重增加。总的来说，这些数据表明正常的眼部和血管的生长以及体重的积累与血液的灌注速度无关，从而支持了同步性的假设-心脏开始跳动并在实际需要对流血流之前产生血流到组织。

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