Review Article (RESPNB_2019_334-R3) What Are Appropriate Values of Relative Krogh Diffusion Constant of NO against CO and of Theta-NO in Alveolar Septa?

Publication date: Available online 14 February 2020Source: Respiratory Physiology & NeurobiologyAuthor(s): Kazuhiro Yamaguchi, Takao Tsuji, Kazutetsu Aoshiba, Hiroyuki Nakamura, Shinji AbeAbstractObjectivesTo propose new physical constants for NO and CO (Krogh diffusion constant ratio (KDNO/CO) and specific blood conductance for NO (θNO)) for calculating DMCO and Vc, according to Roughton-Forster’s equation (J. Appl. Physiol. 11: 290-302, 1957) from simultaneous DLNO and DLCO measurements.Results and conclusions(1) The Graham’s law is unacceptable for determining KDNO/CO because CO does not fulfil all the conditions of an “ideal” gas. We have re-estimated KDNO/CO in a new way based on difference in molar volumes of two gases (molar volume theory). The KDNO/CO thus decided is 2.34. (2) θNO 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 θO2 can be harvested from O2 release kinetics in presence of high concentration of dithionite, which effectively removes the unstirred water layer-elicited effect. Multiplication of erythrocyte θO2 by erythrocyte KDNO/O2 equals erythrocyte θNO, 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 θNO decided from rapid-mixing experiments may...
Source: Respiratory Physiology and Neurobiology - Category: Respiratory Medicine Source Type: research