Résumé
Objective To investigate the effect of Glutamine (Gln) on heat stress-induced dysfunction of intestinal epithelial barrier. Methods Human intestinal epithelial Caco-2 cells were pre-incubated with Gln for 24h and then exposed to heat 43℃ for 1h. Cell counting kit-8 (CCK-8) was used to detect the cellular proliferation with various concentrations of Gln and choose an optimum concentration for subsequent experiments. The barrier integrity was measured by transepithelial electrical resistance (TEER) and horseradish peroxidase (HRP) permeability. Levels of tight junction protein occludin and ZO-1 were analyzed by Western blotting. Cytoskeleton using Coomassie blue staining was observed by microscopy. Results At 0.7mmol/L concentration, Gln showed the most effective cell proliferation compared with other concentration groups (P<0.05). Therefore, 0.7mmol/L Gln was used as effective concentration in following experiments. Gln attenuated the TEER decrease and impairment of intestinal permeability induced by heat exposure compared with 43℃ group (P<0.01). The expressions of occludin and ZO-1 were significantly elevated by pretreatment with Gln. The distortion of cytoskeleton was also effectively prevented. Conclusion 0.7mmol/L Gln is potentially beneficial for protecting against heat stress-induced permeability dysfunction and epithelial barrier damage.