OBJECTIVETo examine the effect of acute incisional pain on the expression of connexin 43 in rat spinal cord dorsal horn.

METHODSEighty rats were assigned into control group without any treatment and incisional pain group with incision surgery. For paw incisions, a 1-cm longitudinal incision was made through the skin and fascia of the plantar aspect of the right hind paw. After surgery, the 50% paw withdrawal threshold (PWT) was assessed in response to a tactile stimulus with calibrated von Frey monofilaments at 1, 2, 4 and 24 h, respectively. The spinal cord dorsal horn of rats was isolated at 1, 2, and 4 h after the surgery to assess the expression of connexin 43 using Western blotting and immunofluorescence assay.

RESULTSThe 50% PWT of the rats was significantly decreased after the incision surgery, and this decrement was the most obvious at 2 and 4 h. Western blotting and immunofluorescence assay showed that the expression of connexin 43 in the spinal cord dorsal horn was significantly increased in rats receiving the surgery especially at 2 and 4 h after the surgery.

CONCLUSIONIncision surgery induces an significant increase in connexin 43 expression in rat spinal cord dorsal horn, suggestting an potential role of connexin43 in postoperative incisional pain.