Enzyme therapy and spinal cord regeneration: A fluorescence microscopic evaluation

Enhanced spinal cord regeneration and return of function has been claimed to follow enzyme therapy. We investigated the effects of mucolytic and proteolytic enzymes on central catecholaminergic fibers after spinal cord transection. The transections were carried out at midthoracic level using 62 young adult female rats. After surgery all animals received daily administration of lydase, or a combination of trypsin and elastase, or saline into the wound site for 14 days. Two weeks, 4 weeks, or 6 months after transection the animals were killed, and spinal cords were removed and processed for fluorescence microscopy. By 2 or 4 weeks, there was no significant growth of fluorescent axons into the lesion gap. In all three treatment groups, some fibers had entered the lesion gap by 6 months, but none had traversed the entire gap. Under the conditions of our experiment, enzyme therapy did not significantly enhance axonal growth in catecholaminergic pathways of the transected spinal cord.