Background: The corticotropin releasing factor (CRF) family of neuropeptides, CRF and the
Urocortins, and their receptors are present not only within the central nervous system but also in the
periphery at various locations and at the sites of inflammation where they influence its progress in a
complex local / paracrine manner.
Objective and Methods: This review summarizes current knowledge regarding the regulation of inflammatory
process by CRF family of neuropeptides and receptors with a special sight into their role in
inflammatory pain and in chronic low grade inflammation that occurs in obesity. For this purpose, we
searched for relevant peer-reviewed research articles using bibliographic databases.
Results: The CRF neuropeptides are either produced locally, by components of the inflammatory response
or they may reach the inflammation sites via postganglionic sympathetic and sensory afferent
nerve transport. It now appears that most immune cells taking part in the inflammatory process express
CRF receptor type 1 (CRF1R) and type 2 (CRF2R) and thus represent targets of CRF neuropeptides.
Indeed, mast cells, monocytes / macrophages, neutrophils and other types of immune cells express both
types of the CRF receptors. In addition to their role in the pathophysiology of inflammation, CRF and
its receptors also exert modulatory effects on inflammatory pain. Finally, it now appears that the CRF
system is also present in adipose tissue and may play a crucial role in the development of the chronic
low grade inflammation, which is characteristic of obesity.
Conclusion: The local effects of the CRF family of neuropeptides can be either pro- or antiinflammatory
depending on concentration of each type of neuropeptide present and the ratio of the local
expression of their receptors CRF1R and CRF2R.