Modeling of impact of gas molecular diffusion on nitric oxide expired profile.

نویسندگان

  • Alain Van Muylem
  • Claire Noël
  • Manuel Paiva
چکیده

Present descriptions of nitric oxide (NO) transport in the lungs use two compartment models: airway compartment without mixing and alveolar compartment with perfect mixing. These models neglect NO molecular diffusion in the airways. To assess the impact of axial diffusion on expired NO profile, we solved a transport equation that incorporated diffusion, convection, and NO sources in the symmetrical Weibel model of the lung. When NO parameters computed from experimental data with the two compartment models are used in our model as NO sources, simulated end-expired NO is 29-45 and 64-78% of experimental values at expiratory flows of 50 and 2,000 ml/s, respectively. These lower values are because of NO axial diffusion: During expiration, NO back diffusion (opposed to convection) prevents some NO from being expired, so a two- to fivefold increase of airway NO excretion is necessary to simulate end-expired NO consistent with experimental data. We conclude that, insofar as a significant amount of NO is produced in small airways, models neglecting NO axial diffusion underestimate excretion in the airways.

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Lattice Boltzmann modeling of two component gas diffusion in solid oxide fuel cell

In recent years, the need for high efficiency and low emission power generation systems has made much attention to the use of fuel cell technology. The solid oxide fuel cells due to their high operating temperature (800 ℃ -1000 ℃) are suitable for power generation systems.Two-component gas flow (H2 and H2O) in the porous media of solid oxide fuel cell’s anode have been modeled via lattice Boltz...

متن کامل

Contribution of type I NOS to expired gas NO and bronchial responsiveness in mice.

Nitric oxide (NO) can be measured in the expired gas of humans and animals, but the source of expired NO (FENO) and the functional contribution of the various known isoforms of NO synthase (NOS) to the NO measured in the expired air is not known. FENO was measured in the expired air of mice during mechanical ventilation via a tracheal cannula. FENO was significantly higher in wild-type B6SV129J...

متن کامل

Modeling gas phase nitric oxide release in lung epithelial cells.

Nitric oxide (NO) is present in exhaled breath and is generally considered to be a noninvasive marker of airway inflammation, and is thus of particular relevance to monitoring asthma. NO is produced when L-arginine is converted to L-citrulline by NO synthase (NOS); however, L-arginine is also the substrate for arginase and both enzymes are upregulated in asthma. Recent reports have speculated t...

متن کامل

Standardisation and application of the single-breath determination of nitric oxide uptake in the lung.

Diffusing capacity of the lung for nitric oxide (DLNO), otherwise known as the transfer factor, was first measured in 1983. This document standardises the technique and application of single-breath DLNO This panel agrees that 1) pulmonary function systems should allow for mixing and measurement of both nitric oxide (NO) and carbon monoxide (CO) gases directly from an inspiratory reservoir just ...

متن کامل

Impact of Cryopreservation Process on Viability, Nitric Oxide and DNA Apoptosis in Fertile Human Spermatozoa

Introduction: Infertility is a common phenomenon in modern societies. Today, use of assisted reproductive technologies (ARTs) for treatment of infertility is common, and cryopreservation is one of these technologies. Cryopreservation has impact on the function and percentage of fertility of human sperm. In this study, motility, viability, nitric oxide, and DNA apoptosis were assessed before and...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:
  • Journal of applied physiology

دوره 94 1  شماره 

صفحات  -

تاریخ انتشار 2003