Effects of inhalation of different concentrations of sevoflurane on pulmonary inflammatory response in rats

Objective To investigate the effects of inhalation of different concentrations of sevoflurane on pulmonary inflammatory response in rats. Methods One hundred and twenty adult Wistar rats of both sexes weighing 200-250 g were randomly divided into 4 groups: Ⅰ control group breathing room air (group C, n = 12);Ⅱ oxygen group breathing 40% O2(group O, n = 36);Ⅲ and Ⅳ sevoflurane groups breathing 1.5% and 3.0% sevoflurane in 40% O2 respectively (group S1, S2, n = 36). Group Ⅱ was further divided into 3 subgroups according to the duration of 40% O2 inhalation 4 h, 8 h and 10 h. Group Ⅲ and Ⅳ were further divided into 3 subgroups ( n = 12 each) breathing sevoflurane for 4 h, 8 h and 8 h followed by 2 h O2 (40%) inhalation. The animals were sacrificed at the end of O2 or/and sevoflurane inhalation. Broncho-alveolar lavage was performed in 6 animals in each subgroup. The TNF-α concentration in broncho-alveolar lavage fluid was determined. The TNF-α mRNA expression and MPO activity in the lung tissue were measured in the other 6 animals in each subgroup. Results Inhalation of 1.5% or 3.0% sevoflurane for 4 or 8 h did not induce inflammatory response in the lung as compared with animals breathing room air or 40% O2 . Conclusion Exposure to sevoflurane does not induce pulmonary inflammatory response in rats breathing spontaneously. Key words: Inflammation; Lung; Anesthesia,inhalation; sevoflurane