Smoke inhalation injury represents a major cause of mortality in
burn patients and is associated with a high incidence of pulmonary complications.
Glutamine (GLN) is considered a conditionally
essential amino acid during
critical illness and injury. However, whether GLN could attenuate
lung injury caused by
smoke inhalation is still unknown. The purpose of this study is to investigate whether GLN has a beneficial effect on
smoke inhalation induced
lung injury. In our present work, rats were equally randomized into three groups:
Sham group (ambient air inhalation plus GLN treatment), Control group (
smoke inhalation plus physiological saline) and GLN treatment group (
smoke inhalation injury plus GLN treatment). At sampling, bronchoalveolar lavage fluid was performed to determine total
protein concentration and pro-inflammatory
cytokine levels. Lung tissues were collected for wet/dry ratio, histopathology,
hydroxyproline and Western blotting measurement. Our results exhibited that GLN attenuated the lung histopathological alterations, improved pulmonary oxygenation, and mitigated
pulmonary edema. At 28days post-injury, GLN mitigated
smoke inhalation-induced excessive
collagen deposition as evidence by Masson-Goldner trichrome staining and
hydroxyproline content. GLN mitigated
smoke inhalation-induced lung inflammatory response, and further prevented the activity of
NF-kappa-B. More importantly, results from Western blotting and Immunohistochemistry exhibited that GLN enhanced the expression of HSF-1, HSP-70 and HO-1 in lung tissues. Our data demonstrated that GLN protected rats against
smoke inhalation-induced
lung injury and its protective mechanism seems to involve in inhibition inflammatory response and enhancing HSP expression.