Levels of vasodilators (SP, CGRP) and vasoconstrictor (NPY) peptides in early human burns

An intact nociceptor system of primary afferent sensory nerves is important for the initiation of the inflammatory process and successful tissue repair. Dysfunction of this system could be a contributing factor for delayed wound healing in humans. We examined the levels of vasodilators [substance P (SP), calcitonin gene-related peptide (CGRP)] and a vasoconstrictor peptide [neuropeptide Y (NPY)] in the peripheral blood samples of patients with burns covering from 20 to 75% of body surface area. Thirteen patient samples were obtained immediately on admission (OA), which was within 12 h of the thermal injury, and 24 h post-admission (PA). Enzyme immunoassay techniques were used for the measurement of the neuropeptides. In addition, an inflammatory marker, tumour necrosis factor-alpha (TNF-alpha), and a myofibrillar protein, creatine kinase (CK), were examined and compared with levels in 13 control subjects. CGRP was high OA and the levels were maintained PA (P < 0.05). SP was also significantly high at both sampling times (P < 0.05). Although TNF-alpha and NPY were somewhat higher in the patients' samples than in the control samples, these levels were not statistically significant (P = NS). CK was higher OA (P < 0.01) than PA (P < 0.04), compared to controls. Plasma levels of SP and CGRP increased significantly in patients with thermal injuries. These peptides may yet be another group of neuromodulators playing a significant role in immune, pain, inflammatory and wound healing in burns.