High intestinal vascular permeability in a murine model for Hirschsprung's disease: implications for postoperative Hirschsprung-associated enterocolitis.

Purpose: Intestinal vascular permeability (VP) in a murine model for Hirschsprung's disease (HD) and postoperative Hirschsprung-associated enterocolitis (HAEC) were investigated.

Methods: Intestinal VP was determined using a Miles assay using 1% Evans blue injected into a superficial temporal vein of newborn endothelin receptor-B KO HD model (KO) and syngeneic wild-type (WT) mice (n = 5, respectively). Extravasated Evans blue in normoganglionic ileum (Ng-I), normoganglionic proximal colon (Ng-PC) and aganglionic distal colon (Ag-DC) was quantified by absorbance at 620 nm. Quantitative polymerase chain reaction (qPCR) for Vascular Endothelial Growth Factor A (VEGF-A), VEGF-B, CDH5, SELE and CD31, and immunofluorescence for CD31 were performed.

Results: VP was significantly higher in Ng-I, Ng-PC, and Ag-DC from KO than WT (p < 0.01, p < 0.05, and p < 0.05, respectively). qPCR demonstrated upregulated VEGF-A in Ng-I and Ag-DC, VEGF-B in Ng-I, and SELE in Ng-I and Ng-PC (p < 0.05, p < 0.05, p < 0.05, p < 0.01 and p < 0.05, respectively), and downregulated CDH5 in Ng-I and Ng-PC from KO (p < 0.05, respectively). Expression of CD31 mRNA in Ng-I and Ag-DC from KO was significantly higher on qPCR (p < 0.05) but differences on immunofluorescence were not significant.

Conclusions: VP may be etiologic for postoperative HAEC throughout the intestinal tract even after excision of aganglionic bowel.