[Improvement of method to produce septic shock model of rats].

Objective: To investigate the feasibility of method improved for developing septic shock rats model.
Methods: Studies were performed on 60 adult male Sprague-Dawley rats. They were randomized into sham group and standard CLP (J Group) group (n = 20), A (n = 10), B (n = 10), C (n = 10) group and J group was further to two subgroups (n = 10) J1 and J2 group. The ligated distance of A, B and C group were 20%, 30%, 50% of the cecum respectively. Standard CLP procedures were made in J group as described previously. Sham group just sham operated. MAP was monitored continuously in A, B, C and J1 groups for 5h, and the MAP dropped to 70% of the baseline was defined as septic shock, MAP was monitored for more than 10 hours until it reached 70% of baseline or lower in the J2 group. The white blood cell count, endotoxin and histopathological changes in lung and renal tissue were observed in each groups.
Results: At 5h after operation, there is no change of MAP in sham, J1, A and B groups, but it dropped to 70% of the baseline [(73 ± 10) mmHg] in C group. Compared with sham group, the level of endotoxin [(17 ± 5) vs (456 ± 28) vs (596 ± 29) vs (982 ± 11) vs (209 ± 40) pg/ml] and white cell count [(6.3 ± 3.7) vs (4.6 ± 1.4) vs (3.7 ± 1.2) vs (3.3 ± 2.6) vs (4.2 ± 1.2)×10(9)/L] was significantly higher and lower respectively in A, B, C and J1 groups. Obvious pulmonary and nephridia tissue edema, inflammatory cell infiltration was observed in C group, but the inflammatory cell infiltration was not found in A, B and J1 groups, The manifestations of J2 group rats is similar with C group.
Conclusions: The rat model produced by ligating 50% cecum can reproduce the pathophysiology of septic shock, and the time needed to prepare septic shock was significantly shorter. The improved model has application value for septic shock study.