Citations

Conventional resuscitation (CR) from hemorrhagic shock (HS) results in gut and liver hypoperfusion, organ and cellular edema, and vital organ injury. Adjunct direct peritoneal resuscitation (DPR) with dialysate prevents gut vasoconstriction, hypoperfusion, and injury. We hypothesized that DPR might also improve hepatocellular edema, inflammation, and injury. Anesthetized male SD rats were assigned to groups ( n = 8/group): 1) sham (no HS); 2) HS (40% MAP/60 min) + intravenous fluid conventional resuscitation [CR; shed blood + 2 vol saline (SAL)/30 min]; 3) HS+CR+DPR (30 ml ip 2.5% glucose dialysate); or 4) HS+CR+SAL (30 ml ip saline). Histopathology showed lung and liver injury in HS+CR and HS+CR+SAL up to 24-h postresuscitation (post-RES) that was not in shams and which was prevented by adjunct DPR. Wet-to-dry weight ratios in HS+CR revealed organ edema formation that was prevented by adjunct DPR. HS+CR and HS+CR+SAL had 34% mortality by 24-h post-RES, which was absent with DPR (0%). Liver IFN-γ and IL-6 levels were elevated in CR compared with DPR or shams. TNF-α mRNA was upregulated in CR/sham and DPR/sham. IL-17 was downregulated in DPR/sham. CXCL10 mRNA was upregulated in CR/sham but downregulated in DPR/sham. Despite restored central hemodynamic performance after CR of HS, liver blood flow was compromised up to 24 h post-RES, and the addition of DPR restores and maintains liver perfusion at 24-h post-RES. DPR prevented liver injury, histological damage, and edema formation compared with CR alone. DPR provided a mitigating anti-inflammatory dampening of the systemic inflammatory response. In all, these effects likely account for improved survivorship in the DPR-treated group.

Intestinofugal neurons sense and receive information regarding mechanical distension of the bowel and transmit this information to postganglionic sympathetic neurons in the prevertebral ganglia. Previous studies have demonstrated that trinitrobenzene sulfonic acid (TNBS)-induced colitis is associated with a loss of myenteric neurons that occurs within the first 12 h following the inflammatory insult. The purpose of this study was to test the hypothesis that intestinofugal neurons are among the myenteric neurons lost during TNBS-induced colitis. The retrograde tracing dye Fast Blue was used to label intestinofugal neurons, and immunohistochemical staining for the RNA-binding proteins HuC/D was used to count all myenteric neurons. Ongoing synaptic input to neurons in the guinea pig inferior mesenteric ganglion (IMG) was recorded via conventional intracellular electrophysiology. In control preparations, intestinofugal neurons account for 0.25% of myenteric neurons. In the distal colon of TNBS-treated animals, the proportion of intestinofugal neurons was reduced to 0.05% (an 80% reduction) within the region of inflammation where 20–25% of myenteric neurons were lost. Neither intestinofugal neurons specifically nor myenteric neurons were reduced in more proximal uninflamed regions. There is a reduction in the frequency of ongoing synaptic potentials in visceromotor neurons of the IMG at 12 and 24 h and 6 and 56 days after TNBS. Collectively, the results of this study suggest that intestinofugal neurons are among the myenteric neurons lost during inflammation and may be selectively targeted. Because intestinofugal neurons are a major driver of sympathetic output to the gut, the loss of intestinofugal neurons may have a profound pathophysiological significance.