Year: 1996
Type: article
Abstract: Oxidant/antioxidant imbalance in smokers and chronic obstructive pulmonary disease An imbalance between oxidants and antioxidants has been proposed in the pathogenesis of chronic obstructive pulmonary disease (COPD).'Although much research has focused on the protease/antiprotease theory of the pathogenesis of COPD, particularly emphysema, less attention has been paid to the role of the oxidant/antioxidant im- balance in this condition.This is surprising since cigarette smoke, which is the major risk factor for the development of COPD, contains 10'7 oxidant molecules per puff of which 1014 are oxygen free radicals.2There is a delicate balance between the toxicity of oxidants and the protective function of the intracellular and extracellular antioxidant defence systems which is critically important for the main- tenance of normal pulmonary cellular functions.3In this editorial we will examine the oxidant/antioxidant imbalance in smokers and patients with COPD to determine if there is enough evidence to warrant therapeutic trials with anti- oxidant therapy in patients with COPD.Cigarette smoke is a complex mixture of over 4700 chemical compounds including high concentrations of ox- idants and free radicals present in both the gas phase and the tar phase of cigarette smoke.24Those in the gas phase are both organic and inorganic including reactive oxygen species and free radicals, aldehydes, peroxides and oxides of nitrogen.In the tar phase radicals are stable and predominantly organic, such as semiquinone which can react to produce superoxide anion (02).Short lived radicals in the gas phase of cigarette smoke may be quenched immediately in the epithelial lining fluid (ELF); however, redox reactions in cigarette smoke condensate may produce reactive oxygen intermediates for a considerable time.'In normal lungs there are 50-70 on August 14,
Source: Thorax
DOI: 10.1136/thx.51.4.348
Institution: Edinburgh Royal Infirmary
Language: English
Subfield: Pulmonary and Respiratory Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
Funder: British Lung Foundation
OpenAlex ID: W2135297085