Within the pulmonary epithelial lining layer (ELF), antioxidants such as ascorbic acid (AH(2)) and glutathione (GSH) react with inhaled nitrogen dioxide ((*)NO(2)) to produce reactive oxygen species (ROS) that induce cellular oxidation. Because the ELF contains unsaturated fatty acids (UFA), which potentially react with (*)NO(2) and/or the antioxidant-derived ROS, we studied the influence of aqueous phase model UFA [egg phosphatidylcholine (EggPC) liposomes] on exposure-induced oxidation and nitration of membranes. Our lung surface model used gas phase (*)NO(2) exposures of immobilized red cell membranes (RCM) overlaid with defined aqueous phases. Acetyl cholinesterase (AChE) activity, TBARS, and 3-nitrotyrosine (3-NT) were used to assess protein and lipid oxidation and RCM nitration, respectively. During (*)NO(2) exposure, AH(2) and GSH induced AChE loss and TBARS, which were unchanged with buffer only. Exposures of EggPC generated extensive TBARS but not AChE loss; addition of AH(2)/GSH to EggPC resulted in smaller AChE declines and fewer TBARS. 3-NT formation occurred with or without EggPC, low concentration antioxidants, SOD, catalase, or DTPA, but was inhibitable by desferrioxamine or high antioxidant concentrations. The data suggest that reaction/diffusion limitations govern (*)NO(2) distribution, that (*)NO(2) per se directly nitrates tyrosine residues within hydrophobic regions, and that the induction of secondary oxidative processes is dependent on nonlinear relationships among (*)NO(2) flux rates, antioxidant concentrations, and diffusivity of secondary reactive species.

Download full-text PDF

Source
http://dx.doi.org/10.1016/s0891-5849(02)01370-9DOI Listing

Publication Analysis

Top Keywords

epithelial lining
8
oxidation nitration
8
ache loss
8
antioxidant concentrations
8
*no2
7
influence epithelial
4
lining fluid
4
fluid lipids
4
lipids no2-induced
4
no2-induced membrane
4

Similar Publications

Low-grade mucinous neoplasm originating from intestinal duplication: a case report and review of the literature.

World J Surg Oncol

January 2025

Cancer Center, Department of Pathology, Zhejiang Provincial People's Hospital, Affiliated People's Hospital, Hangzhou Medical College, 158 Shangtang Road, Hangzhou, Zhejiang, 310014, China.

Background: Low-grade mucinous neoplasms typically originate from the appendix and are characterized by a lining of low-grade mucus-secreting columnar epithelial cells and smooth muscle. However, atypical origins can occur, as demonstrated in this case report.

Case Presentation: We present a case involving a 33-year-old male who, upon physical examination, was found to have an abdominal mass.

View Article and Find Full Text PDF

Objective: To investigate the disposition of enrofloxacin and its active metabolite, ciprofloxacin, in plasma, pulmonary epithelial lining fluid (PELF), peritoneal fluid, and CSF in horses following IV administration of enrofloxacin at doses of 5 mg/kg and 7.5 mg/kg of body weight.

Methods: 6 healthy, mature mares were randomly assigned to receive a single dose of enrofloxacin at either 5 mg/kg or 7.

View Article and Find Full Text PDF

Multiphase Radical Chemical Processes Induced by Air Pollutants and the Associated Health Effects.

Environ Health (Wash)

January 2025

College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China.

Air pollution is increasingly recognized as a significant health risk, yet our understanding of its underlying chemical and physiological mechanisms remains incomplete. Fine particulate matter (PM) and ozone (O) interact with biomolecules in intracellular and microenvironments, such as the epithelial lining fluid (ELF), leading to the generation of reactive oxygen species (ROS). These ROS trigger cellular inflammatory responses and oxidative stress, contributing to a spectrum of diseases affecting the respiratory, cardiovascular, and central nervous systems.

View Article and Find Full Text PDF

Squamous cell carcinoma is the most common malignancy of the head and neck. Pseudovascular squamous cell carcinoma (PSCC) is a rare variant that occurs commonly in the skin of the head and neck. However, oral cavity involvement is extremely rare, with only a few cases reported to date.

View Article and Find Full Text PDF

Background: Alpha-1 antitrypsin (AAT)-deficient individuals have a greater risk for developing COPD than individuals with normal AAT levels.

Methods: This was a double-blind, randomised, parallel group, placebo-controlled trial to examine the safety and tolerability of "Kamada-AAT for Inhalation" (inhaled AAT) in subjects with AAT deficiency, and to explore its effect on AAT and biomarkers in the lung epithelial lining fluid (ELF). 36 patients with severe AAT deficiency were randomised 2:1 to receive 80 mg or 160 mg inhaled AAT or placebo once daily for 12 weeks.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!