Closed-loop model of intestinal fluid secretion

Mice were given access to 5% dextrose water but not solid food for 24 hours before experiments. Mice were anesthetized with isoflurane and body temperature was maintained during surgery at 36°C–38°C using a heating pad. A small abdominal incision was made to expose the small intestine, and closed mid-jejunal loops (length 2–3 cm) were isolated by sutures. Loops were injected with 100 μL vehicle alone or 100 μg CFTR_act-J027, lubiprostone or linaclotide in vehicle. The abdominal incision was closed with sutures, and mice were allowed to recover from anesthesia. Intestinal loops were removed at 90 minutes and loop length and weight were measured to quantify fluid secretion.