Pre-treatment with glutamine attenuates lung injury in rats subjected to intestinal ischaemia-reperfusion.

Abstract

Glutamine (Gln) is the most abundant amino acid in blood and tissue fluids and is considered to be essential in certain catabolic conditions. A series of studies has shown that glutamine can attenuate cytokine release, reduce organ damage and improve survival in a rat model of endotoxaemia. The hypothesis for this rat model study is that pre-treatment with Gln reduces the expression of ICAM-1 and attenuates lung injury induced by intestinal ischaemia-reperfusion (I/R). Sprague-Dawley rats were randomised into five groups, namely sham group (sham surgery), Gln groups (three different doses) and control group. Lung injury caused by intestinal I/R was evaluated using Evans blue dye concentration and histopathologic examination. The level of myeloperoxidase (MPO) was measured using biochemistry method. The expression of heat shock protein 70 (HSP 70) and ICAM-1 were detected using Western blot and real-time polymerase chain reaction (PCR) methods, respectively. Compared with the control group, rats pre-treated with Gln before intestinal I/R demonstrated decreased Evans Blue content and MPO activities in lung tissue, reduced the expression of ICAM-1, attenuated lung injury evidenced by pathological change compared with lactated Ringer pre-treated rats. Gln administration increased HSP 70 mRNA and protein expression in lung tissue compared with control group. Ischaemia-reperfusion injury increases the expression of ICAM-1 in the lung. This may contribute to the migration, accumulation and activation of neutrophils. Pre-treatment with Gln attenuates rat lung injury and reduces ICAM-1 expression.