Oxidative/Nitrosative Stress and the Pathobiology of Chronic Obstructive Pulmonary Disease
The understanding of the pathobiology of Chronic Obstructive Pulmonary Disease (COPD) has undergone a major change in the past three decades. The classical ‘protease-antiprotease’ hypothesis still holds true, nevertheless, the sequence of the biochemical events which lead to the protease/antipro...
Main Authors: | , , , , |
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Format: | Article |
Language: | English |
Published: |
JCDR Research and Publications Private Limited
2013-03-01
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Series: | Journal of Clinical and Diagnostic Research |
Subjects: | |
Online Access: | https://jcdr.net/articles/PDF/2832/45%20-%204360_PF1(M)_E(C)_F(T)_PF1(M)_PF1(T)_FA(T).pdf |
Summary: | The understanding of the pathobiology of Chronic Obstructive
Pulmonary Disease (COPD) has undergone a major change in
the past three decades. The classical ‘protease-antiprotease’
hypothesis still holds true, nevertheless, the sequence of the
biochemical events which lead to the protease/antiprotease
imbalance have been unraveled. For instance, tobacco smoke, a
primary risk factor for COPD, contains a plethora of reactive Oxygen/
Nitrogen Species (ROS/RNS) that serve to initiate the oxidant/
antioxidant imbalance in the respiratory tract of chronic smokers,
a phenomenon that is amplified if certain other risk factors co-exist
(e.g. a genetic deficiency of the major antiproteases, a suboptimal
antioxidant defense system, airway hyper responsiveness etc.). The
inflammatory response that ensues as a result of the initial occult
exogenous oxidative/ nitrosative stress becomes a secondary
endogenous source of ROS/RNS. This perpetuates the ongoing
lung damage, even though the primary insult may no longer be
present (abstinence). Depletion of the pulmonary antioxidants,
damage to the local antiprotease protective screen, a decreased
immune response, hypersecretion of mucus, superadded infections,
oxygen therapy-induced oxidant production, etc. are some of the
critical factors which account for the oxidative/ nitrosative stressmediated pulmonary as well as extrapulmonary features of COPD.
In the light of the recent developments, remarkable efforts are being
made, either to develop novel therapeutic strategies or to improve
the existing ones, which are aimed at treating different aspects of
the disease. Thus, it is reasonable to recommend antioxidants as a
useful adjunct to the more conventional treatment options, keeping
in view the ‘oxidant/antioxidant’ hypothesis as a unifying theme for
the ‘protease/antiprotease’ theory of COPD. |
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ISSN: | 2249-782X 0973-709X |