Increased Serum Endotoxin and Elevated CD14 and IL-1β Expression in a Rat Model of Cerebrogenic Multiple Organ Dysfunction Syndrome

Abstract

To study the mechanisms underlying cerebrogenic multiple organ dysfunction syndrome (CMODS) through investigation of endotoxin levels and the expression of endotoxin receptor CD14 and interleukin IL-1beta mRNAs in a rat CMODS model. Acute cerebral hemorrhage was induced in Wistar rats by focal intracerebral injection of collagenase into the caudate nucleus. Serum endotoxin levels were quantitated using a chromogenic limulus lysate method; CD14 endotoxin receptor mRNA and IL-1beta mRNA levels in lung and intestine were determined by in situ hybridization. Serum endotoxin levels increased after 12 h, reaching a peak after 24 h, and declined to control levels at 72 h. The increase was statistically significant (P<0.05) compared to unoperated controls and the sham-operated group respectively. CD14 mRNA in lung and intestine increased after 12 h, peaked after 24-36 h, and then declined after 48 h. IL-1beta mRNA levels were also increased in lung and intestine (P<0.05), peaking at 36 h and declining thereafter. Expression levels of both CD14 and IL-1beta mRNAs correlated significantly with serum endotoxin levels (Plt;0.01). We conclude that acute cerebral hemorrhage results in endotoxemia and widespread increases in CD14 and IL-1beta expression. We suggest that acute cerebrovascular challenge leads to a stress/shock response that compromises the intestinal mucosal barrier. In turn, this allows endotoxin translocation into the body that provokes the release of pro-inflammatory lymphokines, leading to a systemic inflammatory response syndrome (SIRS) that culminates in multiple organ dysfunction.