CCI-Induced Neuropathic Pain

A CCI of the common sciatic nerve was performed according to the method described by Bennett and Xie³⁹ with minor modification. After obtaining normal baseline values of PWF on 1 day before surgery, mice were randomly assigned to experimental and control groups. Animals were anaesthetized by i.p injection with Zoeltil^® (1.6 mg/kg, Virbac Korea, Seoul, South Korea) and Rompun^® (0.8 mg/kg xylazine HCl, Bayer Korea, Seoul, South Korea,). The right sciatic nerve was surgically exposed at the mid-thigh level, and 3 loose ligatures of 4–0 chromic gut were placed around the nerve with a 1.0 to 1.5 mm interval between each ligature. Sham mice received surgical opening in the same manner without nerve ligation. After surgery, animals were placed on the heating pad until the recovery from anesthesia. Postoperative MA were measured on 1, 3, 5, 7 days post-surgery. On day 7 after CCI surgery, mice received vehicle (5% DMSO, i.p), BD1047 (30 nmol, i.t.), l-THP (20 nmol for i.p. and 2 nmol for i.t.) or GBP (50 mg/kg, i.p.). After administration of each drug, PWF (%) was measured as described above at every 30 min for 120 min. For mechanism test, i.t. treatment with naloxone (10 nmol, i.t) was performed 30 min prior to i.t. injection of l-THP on a day 7 after CCI surgery. All behavioral analysis were performed blindly.