Chattopadhy adult webcams New webcam sexy video
Overall, our findings implicate tobacco-smoke oxidant(s) as the primary etiopathogenic factor behind both the noncellular and cellular damage mechanisms governing emphysematous lung injury and demonstrate the potential of vitamin C to accomplish holistic prevention of such damage.Cigarette smoking is recognized as the predominant cause of emphysematous lung damage associated with chronic obstructive lung disease (COPD), which presently accounts for almost one-fourth of the global mortality and is projected to become the third largest killer by the year 2020 (1).Although such studies have separately identified various cellular factors sustaining CS-induced emphysema, they have perhaps fallen short of identifying the decisive trigger behind such damage and the precise share of the cellular mediators of such damage compared with the direct xenobiotic-induced lung injury inflicted by CS itself.In fact, what precisely triggers CS-induced emphysema still remains an open question.Amid this query, our present study reveals that even the major cellular pathway associated with CS-induced emphysema, involving the pulmonary Rtp801-mediated activation of NF-κB and i NOS and consequent oxido-nitrosative damage of lung proteins and cellular apoptosis (6), is in fact triggered by the CS oxidants itself.Indeed, CS extract divested of its oxidative potency or neutralized by the antioxidant, ascorbate, or vitamin C failed to elicit characteristic oxido-inflammatory damage of human lung cells, indicating that even the cellular mediators of CS-induced lung damage functionally depend on the oxidant(s) furnished by CS, thus establishing them as the primary trigger for CS-induced emphysema.
) of the lung alveolar air-space expansion, along with extensive breakdown of the major lung structural protein, elastin, and overexpression of MMP-9, the primary lung metalloproteinase involved in protein degradation during emphysema (30) (Fig. The Lm and DI values increased by almost four and six times, respectively, for the CS-treated animals from the 28-d sham-control (air-exposed) values of 0.67 ± 0.03 (Lm) and 13.83 ± 2.32 (DI) to that of 2.44 ± 0.22 (Lm) and 80.76 ± 3.11 (DI).Indeed, immunoblot analysis of the same lysates for protein nitration, a signature of peroxynitrite involvement, revealed significant increase in such modification (Figs. When we subjected part of the above lysates to Oxyblot analysis, for assessing the level of lung protein oxidation, we observed substantial time-dependent oxidative modification of lung proteins due to CS exposure (Fig. In an attempt to examine the relative level of lung protein oxidation caused directly by CS, in comparison with that produced by the lung oxido-inflammatory machinery during CS exposure, we administered dexamethasone, an antiinflammatory glucocorticoid into the animal’s lung through nebulization, to suppress possible contribution of oxido-inflammatory protein oxidation induced by CS exposure.We limited such exposure to only 14 d to avoid possible glucocorticoid resistance through sustained smoke exposure.Such alveolar damage was accompanied by increased cellular apoptosis, evidenced through TUNEL assay (Fig.1) Immunoblots depicting time-dependent changes in lung elastin and MMP-9 levels with increasing CS exposure with corresponding change in pulmonary Bax (proapoptotic marker) and Bcl-2 (anti-apoptotic marker) expression levels. Analysis of associated changes in the pulmonary expression of the three NOS isoforms, i NOS, endothelial NOS (e NOS), and neuronal NOS (n NOS), revealed that after 28 d of CS exposure, i NOS levels increased almost 2.6-fold compared with a modest increase for e NOS (1.6-fold), and almost no change for n NOS (Fig.