动物造模 z-bio 2022-01-25 467

　　Objective: To investigate the mechanism of diaphragmatic diastolic dysfunction in rats with acute sepsis.

　　Methods: Thirty-six male clean-grade SD rats were used. The random number table method was divided into: 12 rats in the sham operation group (S group) and 24 rats in the modeling group (CLP group). The model group underwent cecal ligation and puncture to replicate the sepsis model. After successful model establishment, they were randomly divided into the sepsis CLP-6 h group and the sepsis CLP-12 h group, 12 in each group, 6 h after the operation, respectively. and 12 h to measure single-stimulus muscle twitch (Pt), maximal tetanic force (Po), half-diastolic time (1/2RT), systolic time (TPT), maximal systolic rate of rise (+dF/dt) and maximal relaxation The Fura-2 method was used to determine the maximum calcium uptake rate and release rate of the diaphragmatic sarcoplasmic reticulum, and the Western blotting method was used to detect the expressions of SERCA1, SERCA2 and RyR in the sarcoplasmic reticulum.

　　Results: Compared with the S group, the half-diastolic time of the rats in the 6 h and 12 h groups was significantly prolonged, and the -dF/dt was significantly decreased (P<0.01). The peak release rates of Po and sarcoplasmic reticulum calcium were significantly lower than those in the S group (P<0.01), 6="" p="">0.05); the expressions of SERCA1 and RyR in the diaphragm muscle of the rats in the 12 h after modeling group were significantly decreased (P<0.01) serca2="" and="" -atpase="" activities="" did="" not="" change="" significantly="" p="">0.05).

　　Conclusion: Diaphragmatic contraction and relaxation were significantly impaired within 12 hours of acute phase in rats with sepsis, and the diastolic dysfunction may be related to the decrease of sarcoplasmic reticulum calcium uptake function and the low expression of SERCA1, the sarcoplasmic reticulum release and uptake function and the decrease of RyR expression. Together, they lead to a decline in contractile function.