Effects of tegaserod on spinal c-Fos expression in rats with visceral hypersensitivity after rectal distention / 中华消化杂志

ABSTRACT

Objective To assess the effects of tegaserod on rat with visceral hypersensitivity. Methods Neonatal SD rats were randomized to receive colonic acetic acid irritation between postnatal days 8 and 21 as visceral hypersensitive model (Group H) or by saline intrarectally as control group (Group C). While rats were grown-up, rectal distention (RD) was performed by a balloon rapidly inflated with increasing volumes of saline (0.4, 0.8 and 1.2 ml) for 20 seconds at five-minute intervals. The 5 subgroups of Group H were injected randomly with saline, vehicle (1-methyl-2-thpyrrolidone) or tegaserod at doses of 0.1, 0.3 and 1 mg/kg i.p., respectively. The 2 subgroups of Group C were injected with saline or tegaserod at dose of 1 mg/kg i.p.. RD was performed 10 min after injection and abdominal withdrawal reflex (AWR) was recorded, and then c-Fos expression in spinal cord (L6-S1) was analyzed quantitatively by immunohistochemistry. Results 1) Compared to saline, vehicle did not affect AWR and c-Fos expression. 2) Compared to saline, tegaserod significantly (P