July 29, 2003 -- Bethesda, MD -- Cigarette smoke is the major cause of pulmonary emphysema. This disease involves severe damage to the walls of the air sacs (alveoli), causing the lungs to lose their capacity to expand and contract (loss of elasticity). At that point, the air sacs are unable to completely deflate and are therefore unable to fill with fresh air for adequate ventilation. Two of every 1,000 Americans develop this disease. Scientists know smokers are significantly more likely to develop emphysema compared with nonsmokers, and the seriousness of the disease is directly correlated with the amount of cigarette smoking.
But why cigarette smoke leads to this disease is still open to speculation. Now, a team of researchers from Italy has found that cigarette smoke is a potent source of oxidative stress, DNA damage, and apoptosis for HFL-1 (fibroblast) cells, and is most likely the trigger leading to the development of pulmonary emphysema in smokers' lungs.
Their findings confirm the fears of many in a work and social environment that exposure to second-hand smoke can lead to a deadly and debilitating disease.
Among the different toxic effects of cigarette smoke on human tissues, oxidation of structural and functional molecules and modulation of cell turnover play a major role. One study has hypothesized that cigarette smoke may act by decreasing the expression of vascular endothelial growth factor (VEGF) and its type 2 receptor, thus resulting in lung septal endothelial cell death. Because fibroblasts (stellate or spindle-shaped cells with cytoplasmic processes present in connective tissue) play a pivotal role in remodeling of pulmonary tissue, researchers have exposed fibroblasts to cigarette smoke and have studied two important processes: oxidative stress and apoptosis.
Oxidative stress is a disturbance in the oxidant-antioxidant balance, resulting in potential cell damage. It is involved in many biologPage: 1 2 3 4 Related biology news :1
Contact: Donna Krupa
American Physiological Society
. Fears grow over mad elk disease2
. Fears over ICSI largely groundless say fertility experts3
. Fears of gene-therapy DNA passed to next generation statistically unfounded: Penn geneticists estimates affect FDA gene-therapy policy4
. UCR study says second-hand smoke affects healing5
. Prenatal exposure to second-handsmoke greater for disadvantaged children, study finds6
. Exposures to second-hand smoke lower than believed, ORNL study finds7
. Cigarette smoke causes breaks in DNA and defects to a cells chromosomes, Pitt study finds8
. Wildland fires: After the smoke clears9
. Current smoke alarms pass life-saving tests10
. Physician experts available to speak on California fires and smoke inhalation11
. New technology helps fire managers anticipate smoke problems