Raddatz E, Kucera P
Institute of Physiology, University of Lausanne, Switzerland.
Respir Physiol. 1988 Feb;71(2):133-45. doi: 10.1016/0034-5687(88)90011-4.
The carbon dioxide production of the chick embryo cultured in vitro has been determined during the first 24 h of post-laying development using a non-invasive conductometric microtechnique. The mean CO2 production of the whole blastoderm (1) increased from 16 nmol/h at laying to 231 nmol/h at early neurulation, (2) became dependent on exogenous glucose and (3) was closely linked to mechanical tension generated in the blastoderm (loosening from vitelline membrane resulted in a decrease of 56%). In our experimental conditions, no significant influence of carbonic anhydrase on the CO2 production has been detected. The value of the respiratory exchange ratio varied from about 3 at pregastrular stages to 1 at neurula stage and CO2 was produced transiently in presence of antimycin A. Such results indicate that the source of CO2 is not exclusively mitochondrial and that the relative proportions of mitochondrial and non-mitochondrial CO2 productions might vary significantly throughout the early development. Our findings confirm that the metabolism of the chick embryo becomes more and more oxidative from laying onwards and suggest that the modifications of metabolism observed during the studied period of development could be associated with functional differentiation.
利用一种非侵入性的电导微技术，测定了体外培养的鸡胚在产后发育的最初24小时内的二氧化碳产生量。整个胚盘的平均二氧化碳产生量：（1）从产蛋时的16 nmol/h增加到早期神经胚形成时的231 nmol/h；（2）变得依赖于外源性葡萄糖；（3）与胚盘中产生的机械张力密切相关（从卵黄膜上松开导致减少56%）。在我们的实验条件下，未检测到碳酸酐酶对二氧化碳产生有显著影响。呼吸交换率的值在原肠胚前期约为3，在神经胚期为1，并且在抗霉素A存在的情况下会短暂产生二氧化碳。这些结果表明，二氧化碳的来源并非仅为线粒体，并且在线粒体和非线粒体二氧化碳产生的相对比例在早期发育过程中可能会有显著变化。我们的研究结果证实，从产蛋开始，鸡胚的代谢越来越氧化，并表明在所研究的发育阶段观察到的代谢变化可能与功能分化有关。
