Acute DSS-Induced Colitis in C57BL/6 Mice

Male C57BL/6 mice (19–23 g, 8–10 weeks old) were obtained from Japan SLC, Inc. (Shizuoka, Japan). Male C57BL/6 mice were divided into two groups (n = 5 per group). All C57BL/6 mice were anesthetized with medetomidine (0.3 mg/kg; Kyoritsu Seiyaku Corporation, Tokyo, Japan), midazolam (4 mg/kg; Sandoz K.K., Tokyo, Japan), and butorphanol (5 mg/kg; Meiji Seika Pharma Co., Ltd., Tokyo, Japan) by i.p. injection; then, osmotic pumps (ALZET, Cupertino, CA, USA) for the sustained administration of PPZ2 (2.5 mg/kg/day) or vehicle were implanted intraperitoneally 5 days before DSS administration. After the operation, the surgical wound was sutured, and cefalexin was given to prevent infection. C57BL/6 mice are highly susceptible to DSS-induced colitis, and the administration of 2-3% (w/v) DSS to C57BL/6 mice causes colitis in mice [69 (link),71 (link),72 (link)]. For acute DSS-induced colitis, mice were given 3% (w/v) DSS in drinking water for 7 days. The mice were monitored daily for body weight, rectal bleeding, and stool consistency. Mice were euthanized by an overdose of isoflurane at the colon tissue harvest.