Raddatz E, Kucera P, de Ribaupierre Y
Institute of Physiology, University of Lausanne, Switzerland.
Respir Physiol. 1987 Oct;70(1):1-11. doi: 10.1016/s0034-5687(87)80027-0.
A conductometric micromethod combined with image analysis system has been developed allowing to determine the CO2 production within 'two-dimensional' tissues, i.e., flat and thin cell layers or epithelial sheets. The preparation was mounted into an airtight chamber separated in two compartments by a thin silicone membrane permeable to gases. The lower compartment contained the nutritive medium and the preparation. The upper compartment and a conductivity measuring capillary connected in series were perfused with a solution of Ba(OH)2. The CO2 produced by the tissue precipitated as BaCO3 and the resulting decrease of electrical conductivity was linearly related to the total CO2 production. In addition, the pattern of CO2 production was directly observable as the BaCO3 crystals formed upon the silicone membrane over the regions which produced CO2. The spatial distribution of the crystals was quantified by video image processing and the regional CO2 production evaluated with a spatial resolution of 100 microns. This new microtechnique was originally developed to study the CO2 production in the early chick blastoderm which is a disc 1-5 cells thick. At the stage of young neurula the CO2 production was found to be 235 +/- 37 nmol.h-1 (mean +/- SD; n = 10) per blastoderm and large variations of local CO2 production were detected from one region to another (from 0.6 to 6.5 nmol.h-1.mm-2). These results indicate a high metabolic and functional differentiation of cells within the blastoderm. The possible applications and improvements of such a microtechnique are discussed.
已开发出一种结合图像分析系统的电导微方法，可用于测定“二维”组织（即扁平且薄的细胞层或上皮片层）中的二氧化碳产生量。将制剂安装在一个气密室中，该气密室由一层对气体可渗透的薄硅膜分隔为两个隔室。下部隔室包含营养培养基和制剂。上部隔室和串联连接的电导率测量毛细管灌注有氢氧化钡溶液。组织产生的二氧化碳沉淀为碳酸钡，电导率的降低与总二氧化碳产生量呈线性相关。此外，随着在产生二氧化碳的区域上方的硅膜上形成碳酸钡晶体，二氧化碳产生模式可直接观察到。通过视频图像处理对晶体的空间分布进行定量，并以100微米的空间分辨率评估区域二氧化碳产生量。这种新的微技术最初是为研究早期鸡胚盘（一种1 - 5个细胞厚的盘状物）中的二氧化碳产生而开发的。在幼体神经胚阶段，发现每个胚盘的二氧化碳产生量为235±37 nmol·h⁻¹（平均值±标准差；n = 10），并且检测到从一个区域到另一个区域的局部二氧化碳产生量有很大变化（从0.6到6.5 nmol·h⁻¹·mm⁻²）。这些结果表明胚盘内细胞具有高度的代谢和功能分化。讨论了这种微技术的可能应用和改进。
