Does dexamethasone act in neuropeptides SP and CGRP in neurogenic inflammation of the skin? An experimental study.

PURPOSE To investigate the neuropeptides substance P (SP) and calcitonin gene-related peptide (CGRP) after subcutaneous injection of dexamethasone prior to skin incision in rats. METHODS Twenty seven Wistar-EPM-1 rats were randomly divided into three groups. The sham group (SG) of rats was injected with 0.9 % saline. The second group (Dexa) was injected with 1.0 mg/kg dexamethasone, and the third group (Dexa+) was injected with 10.0 mg/kg dexamethasone. In all groups, the three subcutaneous injections were performed 30 minutes prior to the surgical skin incision and tissue collection. SP and CGRP (15 kDa pro-CGRP and 5 kDa CGRP) were quantified by Western Blotting. RESULTS No statistically significant differences (p>0.05) were found in pro-CGRP, CGRP and SP values in all three groups. CONCLUSION The anti-inflammatory effect of dexamethasone did not occur when the substance P and calcitonin gene-related peptide levels were altered during the neurogenic inflammation process of skin wound healing in rats.