The regeneration of the sympathetic catecholaminergic nerve fibers in the process of burn wound healing in guinea pigs.

In the present study, morphological alterations of cutaneous catecholaminergic nerve fibers in the process of burn wound healing have been investigated by using glyoxylic acid induced fluorescence histochemistry. The sympathetic denervation is detected within 48 hr after burns as well as in various excisions. The regenerating sympathetic fibers are observed on the 7th day after burns. These regenerating fluorescent fibers seem to develop in accordance with the regeneration of blood vessels in the wound margins at various stages of healing. Regenerating sympathetic fibers gradually increase in number and the maximum density of these fibers is found approximately at 2 weeks after burns. Thereafter, the density of the fibers gradually decreases to less than that of sympathetic innervation of intact skin. On the 14th day after burns, dense regenerating fibers are observed around the regenerated arterial vessels in the deep granulation tissue of the wound margins. These fibers may correlate with the degeneration of regenerated blood vessels in the center of the wound because of contracting the blood vessel of the wound margins. Moreover, dense collateral sprouting of regenerating fibers is observed around the degenerative blood vessel in the center of the wound on the 16 day after burns. This sprouting occurs not because of searching after a new target organ following the degeneration of the target organ but because of playing important roles in certain functions during wound healing.