[Expression of Toll-like receptor 2/4 mRNA in myocardium in mice with hemorrhagic shock].

OBJECTIVE: To investigate the effect of hemorrhagic shock without resuscitation on expression of Toll-like receptor (TLR) in myocardium of rats and its significance. METHODS: Forty-five C57BL/6 mice were randomly divided into 3 groups: hemorrhagic group, sham operation group and lipopolysaccharide (LPS) group, with 15 mice in each group. The hemorrhagic shock mouse model was reproduced by heart puncture. Expression levels of TLR2 mRNA and TLR4 mRNA were determined by reverse transcription-polymerase chain reaction (RT-PCR). Left ventricular end-systolic pressure (LVESP) was determined and adopted as an index of left ventricle contractile function. RESULTS: (1)Both hemorrhagic shock and LPS challenge led to a reduction in arterial blood pressure in mice when compared with sham operation group. Both hemorrhagic shock and LPS challenge could result in left ventricle contractile dysfunction when compared with sham operation group. (2)Expression levels for TLR2 and TLR4 genes were upregulated in myocardium to various extents after hemorrhagic shock and LPS challenge, while in contrast the changes were absent in sham operation group. CONCLUSION: (1)The up-regulation of TLR2 and TLR4 genes is closely related with hemorrhagic shock and LPS-induced left ventricle contractile dysfunction, and there may exist a difference in signal transduction pathway between the two pathological conditions. (2)The host ability of innate immune response may be reinforced by the up-regulation of TLR2 and TLR4, whereas overexpression of them may also impair the function of tissues or organs.

[Expression of toll-like receptor mRNA in lung tissue in mice with hemorrhagic shock].

OBJECTIVE: To investigate the influence and its significance of expression of Toll-like receptor mRNA in lung tissue of mice with hemorrhagic shock without resuscitation. METHODS: Forty-five C57BL/6 mice were randomly divided into hemorrhagic shock group, lipopolysaccharide (LPS) group (positive control, 5 mg/kg LPS was injected into caudal vein), and sham-operation group (negative control), with 15 mice in each group. The hemorrhagic shock model was reproduced by heart puncture. The total RNA from lung tissue of mice in each group was extracted by Tripure reagent and the expression of Toll-like receptor 2 (TLR2) and TLR4 mRNA were measured by semi-quantitative reverse transcription-polymerase chain reaction. RESULTS: Hemorrhagic shock and LPS challenge increased lung neutrophil infiltration and erythrocyte diapedesis. The expression of TLR2 mRNA and TLR4 mRNA could be found in normal lung tissues, but they were increased at 0, 1, 2, 4, and 6 hours after hemorrhagic shock and LPS challenge. There was no change in the sham-operation group. CONCLUSION: The increased expression of TLR2 and TLR4 gene in lung tissue after hemorrhagic shock is closely correlated with the onset of acute lung injury. Though the innate immunity is enhanced, the animals are more susceptible to subsequent irritations. Over-expression of TLR2 and TLR4 may induce structural and functional damage to organs.