Analysis of real-time serotonin (5-HT) availability during experimental colitis in mouse

Physiol 298: G446–G455, 2010. First published December 17, 2009; doi:10.1152/ajpgi.00318.2009.—Serotonin (5-HT)-containing entero-chromaffin (EC) cells of the intestine transduce chemical and mechan-ical stimuli from the intestinal lumen by releasing 5-HT on to afferent nerve terminals. Dysfunctional mucosal 5-HT signaling has been implicated in heightened visceral sensitivity and altered motility in patients with inflammatory bowel disease and in animal models. Our aim was to characterize the release and uptake of 5-HT in the mouse dextran sulfate sodium (DSS; 5 % wt/vol) model of colitis. We made electrochemical recordings and used an ELISA assay to determine mucosal 5-HT release and uptake in untreated mice and mice with DSS-induced colitis. Peak and steady-state 5-HT concentrations were measured before and during blockade of the serotonin reuptake transporter (SERT) with 1 M fluoxetine. Electrochemical recordings showed that colons from DSS-treated mice had roughly twice th