Oxidative stress and free radicals in COPD--implications and relevance for treatment.
Oxidative stress occurs when free radicals and other reactive species overwhelm the availability of antioxidants. Reactive oxygen species (ROS), reactive nitrogen species, and their counterpart antioxidant agents are essential for physiological signaling and host defense, as well as for the evolution and persistence of inflammation. When their normal steady state is disturbed, imbalances between oxidants and antioxidants may provoke pathological reactions causing a range of nonrespiratory and respiratory diseases, particularly chronic obstructive pulmonary disease (COPD). In the respiratory system, ROS may be either exogenous from more or less inhalative gaseous or particulate agents such as air pollutants, cigarette smoke, ambient high-altitude hypoxia, and some occupational dusts, or endogenously generated in the context of defense mechanisms against such infectious pathogens as bacteria, viruses, or fungi. ROS may also damage body tissues depending on the amount and duration of exposure and may further act as triggers for enzymatically generated ROS released from respiratory, immune, and inflammatory cells. This paper focuses on the general relevance of free radicals for the development and progression of both COPD and pulmonary emphysema as well as novel perspectives on therapeutic options. Unfortunately, current treatment options do not suffice to prevent chronic airway inflammation and are not yet able to substantially alter the course of COPD. Effective therapeutic antioxidant measures are urgently needed to control and mitigate local as well as systemic oxygen bursts in COPD and other respiratory diseases. In addition to current therapeutic prospects and aspects of genomic medicine, trending research topics in COPD are presented.
Division of Pulmonology, Department of Internal Medicine, Medical University of Graz, Graz, Austria.
Wolfgang
W
Domej
Institute of Physiological Chemistry, Medical University of Graz, Graz, Austria.
Karl
K
Oettl
Clinical Institute of Medical and Chemical Diagnostics, Medical University of Graz, Graz, Austria.
Wilfried
W
Renner
D000818:Animals; D000975:Antioxidants / Q000627:therapeutic use; D015415:Biomarkers / Q000378:metabolism; D018450:Disease Progression; D020022:Genetic Predisposition to Disease; D006801:Humans; D008168:Lung / Q000187:drug effects / Q000378:metabolism* / Q000503:physiopathology; D018384:Oxidative Stress / Q000187:drug effects; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism* / Q000503:physiopathology; D026361:Reactive Nitrogen Species / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism*; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects / Q000378:metabolism
D000975:Antioxidants; D015415:Biomarkers; D026361:Reactive Nitrogen Species; D017382:Reactive Oxygen Species
antioxidants; chronic obstructive pulmonary disease; reactive nitrogen species; reactive oxygen species