Objective    To determine the role of myosin light chain (MLC) phosphorylation in intestinal epithelial barrier dysfunction induced by severe burn injury.     Methods    Forty-eight healthy adult Sprague Dawley rats were randomly divided into control group

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12 and 24 h postburn groups. The intestinal permeability of all rats was measured by fluorescein-isothiocyanate-dextran (FITC-D). The changes of tight junction associated protein ZO-1

F-actin and phosphorylated MLC (PMLC) in intestinal epithelia of the rats were analyzed by immunofluorescence.     Results    The intestinal permeability of the rats increased significantly after burn injury

and peaked at 6 h 3 times higher than the control rats. The increased intestinal permeability was accompanied by the striking reorganization of the tight junction associated protein ZO-1

the damage of the tight junction and the significant increase of PMLC in rats with burned intestinal epithelia.     Conclusion    MLC phosphorylation might play a very important role in the regulation of intestinal epithelial barrier dysfunction after severe burn injury.