The expression of L-selectin at transcription and translation level in hemorrhagic shock rat

To detect the expression changes of L-selectin at levels of transcription and translation in hemorrhagic shock rats and to investigate the role of L-selectin in pathogenesis of trauma and hemorrhagic shock.

The tail-cut rats were set as normal group. The carotid puncture rats were set as control groups (trauma group); hemorrhagic shock model was established as shock group (hemorrhagic shock group). Every group has 8 rats. The surface expression of L-selectin in neutrophils was detected in the acute phase of hemorrhagic shock by flow cytometre. The mRNA expression of L-selectin was detected by reverse transcription polymerase chain reaction (RT-PCR ).

The data showed that there were quantifiable kinetic changes in leukocyte after trauma and shock. N eutrophil L-selectin expression in tail-cut rats showed no significant change (P > 0.05) at different time points. The cell surface expression of L-selectin and its mRNA were up regulated in controls as compared with the normal group. The peak value of surface expression was at 3rd hour and last for 4-5 hours, while the peak value of mRNA was at 5th hour. As compared with the normal group, the values in the experimental group were up regulated in the early stage (P < 0.05), while in late stage they were down regulated after 3 hours (P < 0.05).

The up-regulation of L-selectin in neutrophil after trauma may promote the adhesion of leucocytes to the wall of the venules and the inflammatory response may be benificial to wound healing and enhance the ability of anti-infection.The down-regulation of L-selectin after hemorrhagic shock may be associated with alleviation effects of the excessive adhesion reaction and may improve microcirculation.