Figure 5.

Enteric levels of DA and HVA are higher in the ileum of SERTKO than in the ileum of WT littermates. HPLC with electrochemical detection was used to measure levels of DA, DOPAC, and HVA in the ileum, colon, and brain of SERTKO mice and their WT littermates. A, DA levels in neither the ileum nor the colon of SERTKO mice were significantly different from those in the ileum and colon of their wild-type littermates. B, The level of HVA was significantly greater than that of WT littermate controls in the ileum but not in the colon of SERTKO animals. C, The total level of DA plus its metabolites HVA and DOPAC was also significantly greater in the ileum of SERTKO mice than in their WT littermates, although again, the increase in the colon did not reach statistical significance. D, The level of 5-HT in neither the ileum nor colon of SERTKO mice differed significantly from that in the ileum and colon of wild-type littermate controls. E, The concentration of 5-HIAA, the 5-HT metabolite, in the colon was significantly lower in SERTKO mice than their WT littermates. F, In SERTKO mice, the total of 5-HT and 5-HIAA was significantly lower in both the ileum and colon than in WT animals. ns, Not significant.