Table 4– Calculations of membrane diffusing capacity for nitric oxide (DM,NO), membrane diffusing capacity for carbon monoxide (DM,CO) and pulmonary capillary volume (Vc); see Appendix for explanation and commentary
Data setDM,NO mL·min−1·mmHg−1DM,CO# mL·min−1·mmHg−11/DM,CO mL−1·min·mmHg1/Θbl,CO·Vc mL−1·min· mmHg1/Θbl,CO mL−1·min mmHg·mL−1Vc mL1/Θbl,CO·Vc/(1/TL,CO) ∼ TL,CO red blood cell resistance %Comment
NO blood resistance=0 1/Θbl,NO = 0
A144730.01370.01731.317655Most used Θbl value but at pH 8.0 [3]
B144730.01370.01731.719955Θbl value at pH 7.4 [15]
C144730.01370.01730.824755Θbl thin film exps [16]
Finite NO blood resistance (1/Θbl,NO·Vc)/(1/TL,NO) = 37%
D2301170.00860.02241.315872DM,NO from [10]:
E2301170.00860.02241.717672DM,NO from [10]:
F2301170.00860.02240.823772DM,NO from [10]:
G2300.00260.22+8836§From Roughton–Forster equation and 1/DM,NO and 1/Θbl,NO
  • The calculations for DM,CO and Vc were derived from “normal, resting” transfer factor of the lung for NO (TL,NO; 144 mL·min−1·mmHg−1) and TL,NO/TL,CO ratio (4.5) [1, 12, 19, 2226] (TL,CO=32 mL min−1 mmHg−1); for situations where NO uptake blood resistance is zero (1/DM,NO = 1/TL,NO) or finite (1/DM,NO<1/TL,NO). DM,CO derived from DM,NO for α = 1.97 (NO/CO diffusivity ratio), and Vc derived via Roughton–Forster equation 1 for different experimental values of the blood resistance to carbon monoxide transfer (1/Θbl,CO; at PO2 100 mmHg). Multiply by three to convert to SI units (mmol·min−1·kPa−11) from mL·min−1·mmHg−1. #: α = 1.97; : 1/Θbl,NO·Vc was used not 1/Θbl,CO·Vc; +: 1/Θbl,NO was used not 1/Θbl,CO; §: ∼NO red blood cell resistance % was used not TL,CO red blood cell resistance %.