The effect of live E. coli and endotoxin on mortality following massive bowel resection

Abstract

The distal small intestine and its mesentery contain abundant lymphoid tissues rich in B cells and IgM. An increased mortality due to sepsis has been observed after extensive distal bowel resection (80%) presumably related to excision of gut lymphoid tissue and resultant impairment of humoral immunity. This study compares the effect of live <i>E. coli</i> and endotoxin on mortality following massive distal bowel resection. One-hundred ninety Sprague-Dawley rats (200 g) underwent sterile midline laparotomy. Fifty animals had a sham operation (CONTROL) and the remainder an 80% distal small bowel resection (DBR). At seven days after operation, rats were divided into four groups and received an intraperitoneal challenge with either 10⁸ organisms of live <i>E. coli</i> or 10 mg/kg of <i>E. coli</i> endotoxin (ENDO) and were evaluated for mortality at 72 hr. Mortality was 9% in controls+ENDO rats (2/25) (group I), 12% in CONTROL+<i>E. coli</i> rats (3/25) (group II), 56% with DBR+ENDO (39/70) (group III) and 36% with DBR+<i>E. coli</i> (25/70) (group IV). Mortality was increased in animals with DBR (groups III, IV) compared to controls regardless of the method of challenge (<i>p</i><0.05). Mortality was significantly greater in DBR animals that received an ENDO challenge when compared to those given a challenge with live <i>E. coli</i> (<i>p</i><0.05). These data indicate an increased mortality from both live <i>E. coli</i> sepsis and/or endotoxin challenge in animals with massive distal bowel resection. An LD₁₀ of endotoxin had a greater influence on mortality than live <i>E. coli</i>. These results confirm the observation that massive distal bowel resection increases the risk of mortality related to gram negative sepsis probably due to decreased humoral immunity. Mortality is adversely affected by release of endotoxin and its ultimate effect on vital organs.