Short-Term Systemic Effects of Nose-Only Cigarette Smoke Exposure in Mice: Role of Oxidative Stress

Abstract

Background/Aims: Long–term cigarette smoking (CS) is a major risk factor for respiratory and cardiovascular diseases, and is also known to adversely affect other organs. However, data on the systemic effects of short-term CS exposure (STCSE) are scarce. Presently, using a nose-only exposure system, we evaluated the systemic effects of STCSE in mice. Methods: We assessed the effects of CS generated by 9 consecutive cigarettes per day for 4 days in a nose-only exposure system on cardiovascular, hepatic and renal endpoints evaluated on day 5 in mice. Control mice were exposed to air only. Results: CS significantly increased systolic blood pressure and decreased total nitric oxide plasma concentration. Circulating platelets and erythrocyte numbers were also increased. However, STCSE did not significantly increase thrombosis in pial arterioles and venules. STCSE significantly raised plasma alanine aminotransferase and gamma glutamyl transpeptidase activities, but did not affect urea or creatinine concentrations. Interestingly, while STCSE enhanced the production of reactive oxygen species in heart and kidney and lipid peroxidation in heart, liver and kidneys, it also enhanced the antioxidant activity of superoxide dismutase, probably indicating that STCSE causes adaptive reactions to counterbalance the potentially damaging action of oxygen radicals induced by STCSE. Conclusion: These results suggest that STCSE causes blood pressure increase, hepatotoxicity and oxidative stress in the heart, liver and the kidneys. These data provide information on the initial steps leading to the systemic effects of STCSE, a stage at which the diseases may likely be reversed.

Cardiovascular effects of nose-only water-pipe smoking exposure in mice

“…After 1 wk of acclimatization, animals were randomly divided into air (control) and WPS-exposed groups. Mice were placed in soft restraints and connected to the exposure tower (29,30,33). They were exposed to WPS or air through their noses using a nose-only exposure system (InExpose System, Scireq).…”

“…Homogenates were centrifuged for 10 min at 3,000 g to remove cellular debris, and supernatants were used for further analysis. Protein content was measured by Bradford's method as previously described (29,30).…”

“…ROS were measured in whole cardiac tissue homogenates, which were obtained as described above, using 2=,7=-dichlorofluorescein diacetate (Molecular Probes, Eugene, OR) as a fluorescent probe as previously described (29,30). The results were normalized as ROS produced per milligram of protein.…”

“…The results were normalized as ROS produced per milligram of protein. NADPH-dependent membrane lipid peroxidation (LPO) was measured as thiobarbituric acid-reactive substances using malonedialdehyde as the standard (Sigma-Aldrich, St. Louis, MO) (29,30).…”

New experimental model of exposure to environmental tobacco smoke

“…The nicotine in cigarette smoke is inhaled and metabolized in the liver, producing cotinine, which is detectable in plasma Nicotine is a great harmful component in the cigarette, with destructive and malignant consequences 7,16 . The results show the significant difference in serum levels of Nicotine between the experimental and control group that prove the validity of the method of inhalation.…”