经皮二氧化碳释放量机理的研究

Studies on the Mechanism of Transcutaneous CO_2 Emission

为探讨经皮二氧化碳释放量（ＴＣＥ）的机理，使用ＦＲＥＷＩＬ高灵敏度二氧化碳测定仪进行了ＴＣＥ与温度、电阻（四电极法）相关性的研究。发现ＴＣＥ与温度呈一定的正相关（Ｒ＝０．１９，Ｐ＜０．０１）．与电阻呈一定的负相关（Ｒ＝－０．１８，Ｐ＜０．０１），说明ＴＣＥ与相应部位的能量代谢及组织液含量有关。进行剥离角质层的实验，发现降低角质层厚度可使ＴＣＥ显著增高，说明与皮肤通透性有关。用大面积机械压迫静脉血管，在测试点近心端压迫可使ＴＣＥ显著增加，屏气也可导致其显著增加，说明静脉回流和肺呼吸可通过影响局部二氧化碳回收而影响ＴＣＥ。还发现肌肉作功可显著增加ＴＣＥ，将皮肤由两块肌肉之间移位到肌肉丰厚的地方，ＴＣＥ显著增加，说明肌肉的代谢活动可影响ＴＣＥ。根据上述结果，提出二氧化碳释放速率公式为：ｄｙ／ｄｔ＝ｋｖ（ｄｘ_１／ｄｔ－ｄｘ_２／ｄｔ），ｋ为皮肤的通透性系数，ｖ为组织液含量，ｄｘ_１／ｄｔ为能量代谢生成二氧化碳速率，ｄｘ_２／ｄｔ为循环系统吸收二氧化碳的速率。

Study on the mechanism of transcutaneous CO_2 emission (TCE), the high sensative Frewil CO_2 instrument was used to measure the correlativity between TCE, skin temperature (ST) and skin impedance(SI). The results showed that TCE and ST had positive correlation (r=0.19, P<0.01), the TCE and SI had nagetive correlation (r=-0.18, P<0.01). It illustrated that the TCE related to the local energy metabolism and vdume of tissue fluid. The other study showed that after thinning the corneum, TCE were significantly higher than before which illustrated the ralation between TCE and permeability of skin. The TCE also increasad sitrikingly after mechanical pressing the vein or transit stopping the breath. It means the TCE can be influenced by the backflow of venous blood and respiration. Another experiment showed that the TCE increased in muscle after muscle working. The last experiment showed that when the skin between two muscles move to the centre of muscle, the TCE increased significantly. These two experiments illustrated that the muscle metabolism can influence the TCE. We suggest a femula of TCE arte:dy/dt=k×V (dx,_1/dt-dx_2/dt). The k is permeability of skin to CO_2, V is the volum of tissue fluid, dx_1/dt is the producing rate of CO_2 in local energy metabolism and dx_2/dt is the absorbed rate of CO_2 by blood circulation system.