Abstract:
The main purpose of this experiment is to study the effect(s) of cigarette smoke on morphological changes of type II pneumocytes of 8 weekth female Swiss albino mice. The mice were divided into 7 groups. There are 2 control groups: group C) non-exposed normal mice; group CP) first day non-exposed pregnant mice. The experimental groups consist of s separated groups: group E10) normal mice exposed to cigarette smoke 1, 2 and 3 cigarettes per day for 10 days; group E20) normal mice exposed to cigarette smoke 1, 2 and :3 cigarettes per day for 20 days; group E30) normal mice exposed to cigarette smoke 1, 2 and 3 cigarettes per day for 30 days; group E30(10) normal mice exposed to cigarette smoke 1, 2 and 3 cigarettes per day for 30 days with no-smoke period for 10 days and the last group Ep) first day pregnant mice exposed to cigarette smoke 1, 2 and 3 cigarettes per day until delivery. The mice from control group C and experimental group E10, E20, E30 and E30(10) were sacrificed and lung specimen were collected at the completion of the experiment. The body weights and Crown-Rump lengths of all first day newborns of both control and experimental groups were recorded and they were fed normally for 25 days. Newborns were sacrificed at random and their lungs were collected. All lungs of each group were processed for both light microscopy and transmission electron microscopy. It was found that the interalveolar septum of lung were thinner, alveoli were dilated and the number of type II pneumocytes which lined the interalveolar septum were decreased significantly (p<0.05) among mice exposed to cigarette smoke at higher quantities and longer periods. Among the groups with highest exposure (3 cigarettes per day), it was noticed that the number of lamellar bodies in type II pneumocytes were reduced and their mitochondria and Golgi apparatus were with abnormal shape. After a period of 10-day break interval their interalveolar septum was normal but some alveoli still dilated, the number of type II pneumocytes has been resumed but still lower than the control. The body weights and Crown-Rump lengths of newborns with smoke exposed mothers were less than the newborns with non-smoke exposed mothers (p<0.05). The interalveolar septum, size of alveoli and number of type II preumocytes were not different significantly (p>0.05). In conclusion, cigarette smoke causes to danage the interalveolar septum especially the reduced amount of type II pneumocytes and some important organelles which concern the production of surfactant in type II pneumocytes. . The damage was very serious among the higher exposure groups.
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