Effect of glutamine on lung tumor necrosis factor-αin a rat model of LPS-induced acute lung injury

Objective To investigate the effect of glutamine on the expression of tumor necrosis factor-α(TNF-α) in the lung tissue in a rat model of acute lung injury (ALI) induced by lipopolysaccharide (LPS). Methods Fifty male SD rats weighing 200-290g were randomly divided into 5 groups ( n = 10 each) : group A control; group B LPS 5 mg·kg-1 ; group C, D and E received glutamine 0.75 g·kg-1 1 h before (C), together with (D) and 1 h after LPS injection (E) . The animals were sacrificed at 4 h after LPS injection. The lungs were immediately removed for microscopic examination and determination of expression of TNF-αmRNA and protein in the lung by RT-PCR and immunohistochemistry. Results LPS produced inflammatory response and significantly increased the expression of TNF-αmRNA and protein in the lungs. Glutamine given before or together with LPS significantly attenuated the LPS-induced inflammatory response and increase in TNF-αmRNA and protein expression. Conclusion Glutamine given before or together with LPS can protect the lungs from ALI by inhibiting excessive TNF-a production in the lung.