Department of Respiratory Medicine, Tokyo Medical University, Tokyo 160-0023, Japan.
Department of Respiratory Medicine, Tokyo Medical University Ibaraki Medical Center, Ibaraki 300-0395, Japan.
Respir Physiol Neurobiol. 2020 May;276:103415. doi: 10.1016/j.resp.2020.103415. Epub 2020 Feb 14.
To propose new physical constants for NO and CO (Krogh diffusion constant ratio (KD) and specific blood conductance for NO (θ)) for calculating DMCO and Vc, according to Roughton-Forster's equation (Roughton and Forster, J. Appl. Physiol. 11: 290-302, 1957) from simultaneous DLNO and DLCO measurements.
(1) The Graham's law is unacceptable for determining KD because CO does not fulfil all the conditions of an "ideal" gas. We have re-estimated KD in a new way based on difference in molar volumes of two gases (molar volume theory). The KD thus decided is 2.34. (2) θ measured with rapid-reaction, constant-flow method by Carlsen and Comroe (J. Gen. Physiol. 42: 83-107, 1958) may be underestimated by about 40 % due to unstirred water layer surrounding the erythrocyte. (3) Erythrocyte θ can be harvested from O release kinetics in presence of high concentration of dithionite, which effectively removes the unstirred water layer-elicited effect. Multiplication of erythrocyte θ by erythrocyte KD equals erythrocyte θ, the value of which is 6.2 mL/min/mmHg/(mL⋅blood). According to the concepts of Kang et al. (RESPNB. 241: 62-71, 2017) and Borland et al. (RESPNB. 241: 58-61, 2017), in vitro θ decided from rapid-mixing experiments may mirror bulk absorption of NO by erythrocytes. (4) In pulmonary capillaries, NO uptake takes place predominantly in the surface rim of the erythrocyte. This surface absorption of NO increases the θ 10-fold versus bulk absorption of NO to about 60 mL/min/mmHg/(mL⋅blood).
根据 Roughton-Forster 方程（Roughton 和 Forster，J. Appl. Physiol. 11: 290-302, 1957），从同时测量的 DLNO 和 DLCO 中，提出用于计算 DMCO 和 Vc 的新的 NO 和 CO 的物理常数（Krogh 扩散常数比（KD）和 NO 的特定血液传导率（θ））。
（1）Graham 定律不能用于确定 KD，因为 CO 不符合“理想”气体的所有条件。我们根据两种气体的摩尔体积差异（摩尔体积理论）以新的方式重新估算了 KD。由此决定的 KD 为 2.34。（2）Carlsen 和 Comroe（J. Gen. Physiol. 42: 83-107, 1958）采用快速反应、恒流法测量的 θ可能因红细胞周围的未搅动水层而低估约 40%。（3）由于高浓度连二亚硫酸盐有效地去除了未搅动水层引起的效应，因此可以从 O 释放动力学中提取红细胞 θ。红细胞 θ 乘以红细胞 KD 等于红细胞 θ，其值为 6.2mL/min/mmHg/（mL·血液）。根据 Kang 等人的概念（RESPNB. 241: 62-71, 2017）和 Borland 等人的概念（RESPNB. 241: 58-61, 2017），从快速混合实验中确定的体外 θ 可能反映了红细胞对 NO 的整体吸收。（4）在肺毛细血管中，NO 摄取主要发生在红细胞的表面边缘。这种 NO 的表面吸收使 θ 相对于 NO 的整体吸收增加了 10 倍，约为 60mL/min/mmHg/（mL·血液）。
