Objective: To investigate the changes of the mRNA expressions of myocardial cytoskeletal proteins in endotoxemic rats.
Methods: Thirty-seven Wistar rats were randomized into two groups with injection of 10 mg/kg lipopolysaccharide (LPS) or normal saline through the femoral vein. The cardiac function of the rats was monitored continuously for 24 h, and the morphological changes of the cardiac myocytes were observed with HE staining and electron microscope. The mRNA levels of myocardial cytoskeletal proteins including actin, tubulin and desmin were determined by RT-PCR.
Results: No significant difference was found in the number of CD3(+)T lymphocytes in the TILs between different groups. After the immunotherapy, the peLPS injection resulted in significant impairment of the cardiac function and myocardial microstructure of the rats with reduced heart rate and left ventricular systolic pressure (LVSP). The mRNA expression of actin in the cardiac myocytes measured by fluorescence optical density was reduced significantly 8 h after LPS injection, and that of tubulin was decreased significantly 24 h after LPS treatment; desmin mRNA expression showed no significant variation after LPS injection.
Conclusion: LPS can significantly impair the cardiac function of the rats possibly by inducing damages of the myocardial cytoarchitecture and causing changes in the mRNA expressions of such cytoskeletal proteins as actin and tubulin.