Objective: To examine the effect of acute incisional pain on the expression of connexin 43 in rat spinal cord dorsal horn.
Methods: Eighty 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.
Results: The 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.
Conclusion: Incision 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.