Pulmonary emphysema induced by passive smoking: an experimental study in rats

Abstract

We describe a short time model for inducing experimental emphysema in rats by chronic tobacco smoke inhalation. Three groups of male Wistar rats (6 months old) were studied: controls (N = 8), rats intoxicated for 45 days (s-45, N = 7) or for 90 days (s-90, N = 8). The exposed animals were intoxicated 3 times a day (10 cigarettes per exposure period), 5 days a week. Pulmonary damage was assessed by means of functional tests and quantitative pathological examination of the airways and lung parenchyma. The s-45 and s-90 animals were similar in terms of functional residual capacity (FRC) corrected for body weight (FRC/kg) but both groups of smoking rats exhibited significantly higher FRC/kg values than the controls (s-45 = 6.33; s-90 = 6.46; controls = 3.78; P<0.05). When the two groups of smoking rats were pooled together and compared to controls, they showed decreased lung elastance (1.6 vs 2.19; P = 0.046) and increased mean linear intercept (Lm) (85.14 vs 66.44; P = 0.025). The s-90 animals presented higher inflammation and muscular hypertrophy at the level of the axial bronchus than the controls (P<0.05). When smoking groups were pooled and compared to controls, they presented significantly higher inflammation at the lateral level (P = 0.028), as well as airway secretory hyperplasia (P = 0.024) and smooth muscle hypertrophy (P = 0.005) at the axial level. Due to its simplicity, low cost and short duration, this technique may be a useful model to obtain new information about airspace remodeling due to chronic tobacco consumption.

Effect of Cigar Smoking on the Risk of Cardiovascular Disease, Chronic Obstructive Pulmonary Disease, and Cancer in Men

“…Even cigar smokers who do not inhale are exposed to their own environmental tobacco smoke, a clearly documented risk factor for coronary heart disease [40][41][42][43][44] and COPD. [45][46][47] In summary, our data confirm that cigar smoking is related to a moderate increase in the risk of COPD and cancers of the upper aerodigestive tract and lung, and they add new evidence that cigar smoking is associated with a moderate but significant increase in the risk of coronary heart disease. The resurgence of cigar smoking in recent years is a matter of substantial concern.…”

Effect of Cigarette and Cigar Smoking on Peak Expiratory Flow Rate

“…This difference may have contributed to greater reduction in PEFR in cigar smokers compared to cigarette smokers. Further, cigar smokers who do not inhale are exposed to their own environmental tobacco, a clearly documented risk factor for COPD [27][28][29]. This could be another potential reason why cigar smoking may cause maximum reduction in PEFR.…”

Effects of Passive Smoking Associated with Physical Exercise in the Skeletal Muscles of Rats During Pregnancy and Lactation

“…For the fulfillment of this protocol two hermetically sealed chambers were used, one for groups GF and GFN with inhalation of cigarette smoke and the second for the animals of groups GC and GN with inhalation of only compressed air (Cendon et al, 1997).…”