Potentiation of serotonin signaling leads to increased carbohydrate and lipid absorption in the murine small intestine

Enteric serotonin influences intestinal homeostasis and functions as a mucosal growth factor. Previously, we demonstrated increased mucosal surface area and enhanced crypt cell proliferation in serotonin reuptake transporter (SERT)-deficient mice. Therefore, we hypothesized that serotonin-mediated mucosal growth would also result in enhanced carbohydrate and lipid absorption. Wild-type C57Bl/6 (WT) and SERT-knockout (SERTKO) mice were fasted then gavaged with D-xylose or boron-dipyrromethene (BODIPY) FL-C12 medium-chain fatty acid analog. Serum D-xylose and BODIPY concentrations were serially measured from blood drawn at 30 to 360 min post-gavage. Small intestine was harvested from both groups for comparison of morphometric parameters. Area under the curve of plotted graphs was calculated, and means were compared with Student's t-test to a significance of p