Neutral endopeptidase activity is increased in the skin of subjects with diabetic ulcers.

Cutaneous sensory nerves mediate inflammation and wound healing by releasing neuropeptides, such as substance P, which stimulates pro-inflammatory responses by keratinocytes, fibroblasts, and endothelial cells. The cell surface enzyme, neutral endopeptidase, degrades substance P, thereby regulating its biologic actions. We hypothesized that neutral endopeptidase enzymatic activity is increased in chronic wounds and skin from subjects with diabetes.