The Impact Of The Septic Rats Vascular Endothelial Cell Function After Treat With Low Molecular Weight Heparin

Objective:To observe the change of pulmonary vascular endothelial cell(VEC),explore the protection of low molecular weight heparin on pulmonary VEC in sepsis rats and the possible Mechanism,by setting sepsis rat model,detecting apoptosis of pulmonary VEC,expression of s TM and E-selectin protein in serum,and the pathomorphologic change of lung.To explore the possible mechanism and provide a theoretical basis for the treatment of sepsis.Methods:(1) 72 SD rats were randomly divided into 4 groups: the control group(n=18), the sepsis group(n=18), the LPS + UFH group(n=18) and the LPS + LMWH group(n=18). The sepsis group was injected with Lipopolysaccharide(LPS)(4mg/kg). The LPS + UFH group was injected with LPS(4mg/kg)and UFH(100U/kg), the LPS + LMWH group was injected with LPS(4mg/kg)and LMWH(100U/kg). The control group was injected with saline. The four groups were randomly divided into three subsets(6 rats each)and killed the subsets at 6h,12 h and 24 h respectively.(2) Rats were killed at 6th,12 th and 24 th hours after the time of LPS injection, the lung samples were sliced into the paraffin sections and were stained with H.E. The pathological changes were observed by light microscope and the pulmonary VEC apoptotic was detected by Hoechst 33258.(3) We have examined the expression of Bcl-2 and Bax in VEC through immunohistochemistry at each observation point;(4) s TM and s E-selectin of blood plasma caleulated by ELSIA.Result:(1) HE staining showed that the red blood gathered in alveolar spaces and microvascular, and became more aggravate as time goes. Compared with the sepsis model group, the pulmonary oedema and red cell / leukocyte infiltration of LPS + UFH group and LPS + LMWH group have significant improvement(P<0.01), and the LPS + LMWH group was more significant than LPS + LMWH group(P<0.05);(2) Hoechst 33258 staining showed that the sepsis may lead to karyopycnosis of VEC, and as times goes the apoptosis of VEC would be more severe. The VEC apoptosis of LPS + UFH group and LPS + LMWH group were significantly reduce than sepsis model group(P <0.01), and compared with the control group, the apoptotic nuclei of LPS + UFH group significantly increased(P <0.01), the apoptotic nuclei of LPS + LMWH group was less than LPS + UFH group(P <0.05);(3) The results of Bcl-2, Bax detection by Immunohistochemical showed that the expression of Bax in VEC of LPS + UFH group and LPS + LMWH group were less than it in sepsis model group(P <0.05). The expression of Bcl-2 in each group had no statistical significance difference, but the Bax / Bcl-2 reduced more significant than sepsis group(P <0.05). The expression of Bax in LPS + LMWH group was lower than it in LPS + UFH group(P <0.05);(4) We have detected the expression of serum s TM and s E-selectin, and found that the expression of s TM was higher at each observation point(6 h, 12 h and 24 h) than it in the rest group(P <0.01); the expression of s TM in LPS + UFH group and LPS + LMWH group were lower than it in the sepsis model group at each time point(P <0.01), but higher than it in control group(P <0.01), and the expression of s TM in LPS + LMWH group was lower than it in LPS + UFH group(P <0.05). The expression of s E-selectin in sepsis group at each observation point(6 h, 12 h and 24 h) was higher than it in control group(P <0.01). The expression of s E-selectin of LPS + UFH group and LPS + LMWH group were lower than it in the sepsis model group at each observation point(P <0.01).Conclution:(1) The apoptosis of pulmonary VEC,the expression of s TM and s E-selectin in serum,pulmonary edema and cell infiltration significantly increased in the sepsis model group.(2) The protective effection of LMWH inacute lung injury induced by LPS may through anti-inflammatory in fluence on the axis of coagulation and infiammation.