uccessful repair of injured tissues requires diverse interactions between cells, biochemical mediators, and the cellular microenvironment. [1][2][3] Much has been learned about the individual events that are involved in this process, but their integration is clearly far more complex than has been imagined, and the important role of neurogenic stimuli is only recently being recognized.Neurogenic stimuli profoundly affect cellular events that are involved in inflammation, proliferation, and matrix, as well as cytokine and growth factor synthesis. Immune cells regulated by neuropeptides include lymphocyte subsets, macrophages, and mast cells. In addition, neuropeptides may affect the proliferative and synthetic activity of epithelial, vascular, and connective tissue cells. Furthermore, a close interaction between the nervous and the immune systems has become obvious. 4 The peripheral nervous system (PNS), acting through neuropeptides, not only relays sensory information to the central nervous system (CNS) but also plays an effector role in the inflammatory, proliferative, and reparative processes after injury. These effects range from growth factor and cytokine responses to control of local blood flow. Neuropeptides mediate many of the actions important in tissue-nervous system communication.We review the accumulated knowledge about the role of neuropeptides in inflammation as it pertains to tissue repair.
NEUROPEPTIDES OF THE PNSNeuropeptides constitute one of the largest families of extracellular messengers, having a long phylogenetic history. They can act as neurotransmitters, hormones, and paracrine factors.