Possible chemical contribution from chromic gut sutures produces disorders of pain sensation like those seen in man.

Recently, it has been reported that loosely constrictive chromic gut ligatures around the sciatic nerve produce behavioral evidence of neuropathic pain in rats. It has been shown that axonal swelling after ligation results in a constriction injury associated with a decrease in the number of both large-diameter myelinated and small-diameter unmyelinated axons, but the mechanism(s) producing spontaneous pain and thermal hyperalgesia remain largely unknown. The present study systematically evaluated potential mechanisms involved in development of the behavioral changes produced by chromic gut ligatures loosely tied around the sciatic nerve.

Fos-like proteins in the lumbosacral spinal cord following noxious and non-noxious colorectal distention in the rat.

The rat lumbosacral spinal cord was immunocytochemically stained for Fos-like immunoreactivity following repetitive colorectal distention (CRD) to 20, 40 or 80 mm Hg. Following all 3 distention pressures, Fos-like immunoreactive (Fos-ir) nuclei were observed primarily in laminae I-II, V-VII and X, although some labeled nuclei were observed in laminae III-IV. Eighty mm Hg CRD resulted in significantly more Fos-ir nuclei than 20 or 40 mm Hg CRD.