[Effects of cervical chordotomy on systemic inflammatory response and the outcome in rats with endotoxic shock induced by lipopolysaccharide].

OBJECTIVE

To investigate the effects of cervical chordotomy on systemic inflammatory response and the outcome in rats with endotoxemia induced by lipopolysaccharide (LPS).

METHODS

Ninety-two Sprague Dawley (SD) rats were randomly divided into three groups: normal control group (group I, n=8) , endotoxemia group (group II, n=42) and endotoxemia with cervical chordotomy (group III, n=42). Endotoxemia was induced by intra-peritoneal injection of LPS 10 mg/kg. In group III, "cervical chordotomy" was attained by transection of spinal cord at C7 immediately before intra-peritoneal LPS administration. Ten rats of group II and III each were observed for 48-hour survival. The other rats were further divided into four subgroups of 8 animals each, according to the time when the animals were sacrificed . The animals were sacrificed at 3, 6, 12, and 48 hours after intra-peritoneal LPS injection. Heart blood samples were obtained for determination of plasma concentration of norepinephrine [NE, by high performance liquid chromatography (HPLC)] and plasma concentration of interleukin-10 (IL-10) and IL-6 [by enzyme linked immunosorbent assay (ELISA)].

RESULTS

Plasma NE concentration were significantly increased after intra-peritoneal LPS injection in group II and III as compared with group I and were significantly lower in group III than in group II starting from 6 hours after LPS (all P<0.05). Plasma IL-10 concentration was significantly lower at 3 hours and 6 hours while plasma IL-6 concentration was significantly higher after LPS challenge in group II than in group I at all time points (all P<0.05). High transection of spinal cord significantly elevated plasma IL-10 level at 12 hours and 48 hours, lowered IL-6 release at 3, 6, and 12 hours (all P<0.05), and improved 48-hour survival (20% vs. 70%) in group III as compared with group II.

CONCLUSION

Transection of spinal cord at C7 level can ameliorate the systemic inflammatory response induced by endotoxemia thus improving the outcome through elevation in IL-10 level, decreases in IL-6 release, and improves 48-hour survival. This might be attributable to loss of sympathetic nerve function.