Objective To evaluate the therapeutic effect of interrupted peritoneal lavage ( PL ) combined with antibiotics on the severe acute pancreatitis in rats． Methods Fifty-six adult Wistar rats ( 280 g － 350 g) were randomly divided into sham operation ( SO) group，SAP groups of non-antibiotics + non-drainage tube ( SNANT) group，of non-antibiotics + drainage tube( SNAT) group，of antibiotics + drainage tube ( SAT) group，of antibiotics + non-drainage tube( SANT) ，of SAP + PL groups included antibiotic + peritoneal lavage ( APL) group，and of non-antibiotics + peritoneal lavage( NAPL) group，with 8 rats in each group． SNANT and SANT models were produced by slow retrograde infusion of 5% sodium taurocholate solution ( 0． 02ml /100g) into the common biliopancreatic duct in Wistar rats． In the SNAT、SAT、APL and NAPL groups，abdominal cavity drainage tube with side holes was introduced into the abdominal cavity at the right lower quadrant of the abdomen based on the SNANT models，and was tied to the rat tail． Peritoneal lavage was performed with normal saline at ambient temperature and narcosis after 12 hours of successful induction of animal models，once per 12 hours and four times in total． The intraperitoneal injection of antibiotics ( Left oxygen Buddha injection 40 mg /kg + Metronidazole Injection 90 mg /kg) was performed once in every 12 hours after successful induction of animal models in SANT and SAT groups or next to the termination of peritoneal lavage in APL group． Blood sample and pancreatic tissue were obtained after 12 hours of injection of antibiotics and peritoneal lavage． The blood levels of tumor necrosis factor-α ( TNF-α ) ，Interleukin-6 ( IL-6 ) ， Interleukin-8 ( IL-8 ) ，lipopolysaccharide ( LPS ) were measured by enzyme-linked immunosorbent assay ( ELISA) ． The changes of pathological morphology of pancreatic tissue were evaluated and scored under light microscope after staining with hematoxylineosin-stain． Results ( 1) Compared with the SO group，the blood levels of TNF-α、IL-6、IL-8、LPS in SAP groups and SAP + PL groups were increased remarkably ( P ＜ 0． 05) ; Compared with the SNANT group，there were no significantly changes ( P ＞ 0． 05) in the SNAT group and the NAPL group; Compared with the SANT group，there were no significantly changes ( P ＞ 0． 05) in the SAT group and the APL group in the blood levels of LPS、TNF-α、IL-6、IL-8; Compared to the groups without antibiotics including SNANT group，SNAT group and NAPL group，the blood levels of LPS、TNF-α、IL-6、IL-8 in the groups with antibiotics including SANT group，SAT group and APL group were decreased remarkably ( P ＜ 0． 05) ; Compared with the NAPL group，the blood levels of LPS、TNF-α、IL-6、IL-8 in the APL groups were decreased remarkably ( P ＜ 0． 05) ． ( 2) The histological examination of pancreatic tissue showed that: the enlargement of interlobular space，inflammatory infiltration，fat necrosis，hemorrhage，and the destruction or deletion of pancreatic acini were observed in the SAP groups; while in the SAP + PL groups，the enlargement of interlobular space was larger than in the SAP groups，but there was no significantly changes ( P ＞ 0． 05) for the inflammatory infiltration，fat necrosis，hemorrhage，and the destruction or deletion of pancreatic acini between them; there was only dispersive regional edema of interlobular space in the SO group． The total histopathologic scores were significantly increased in SAP groups and PL groups compared to SO group ( P ＜ 0． 05) ， and there was no statistically significant differences between SAP groups and PL groups ( P ＞ 0． 05) ． Conclusion This study suggests that，in the early stage of SAP，interrupted peritoneal lavage combined with antibiotics reduces significantly the blood levels of LPS、TNF-α、IL-6 and IL-8 ( P ＜ 0． 05) ，and it maybe contributed to the reduction of the systemic damage to promote SAP get better and improve the prognosis of SAP．

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