The skin is densely innervated with sensory neuronal fibers that synthesize several neuropeptides, including the eleven residue tachykinin, substance P (SP). Among SP effects are inflammation mediation and subsequent wound healing. Major objectives of this study are to: (1) determine the optimum time and dose of streptozotocin for the development of a diabetic rat model by measurement of SP content and SP containing nerve density; (2) to evaluate SP depletion in cutaneous nerves in the streptozotocin diabetic rat model of type I diabetes, using immunohistochemical analysis; (3) to determine the stability of formulations of SP and SP analogs under different time and temperature conditions; and (4) to develop SP and SP analog treatments for wound healing in the streptozotocin rat model of type I diabetes. The long- term goal is ultimately to develop effective SP therapies for use in promoting wound healing in diabetic patients.