The veitebrate body has at its disposal three different systems, which together help it to maintain homeostasis and to respond to environmental signals: the nervous system. the endocrine system and the immune system. Traditionally, these systems have been studied as separate entities. However, in the interest of stability of the organism, it is essential that these different systems be able to communicate and reciprocally regulate each other's activities [I]. Communication can take place via direct cell-cell contact or through soluble signalling molecules and their specific receptors on target cells. It is hypothesised that the signalling molecules, which are shared between the three systems, are evolutionarily ancient [2]. Among others, endorphins [3, 4], cytokines such as interleukin-l (IL-l) and IL-6 [5-7], honnones such as corticotrophin-releasing factor (CRF) [8, 9] and adrenocorticotrophic hormone (ACTH) [3, 4] and neuropeptides such as substance P and somatostatin [2, to] have been identified as signalling molecules with effects on many different cell types and effector systems. Through its effects on vasodilatation and blood flow the nervous system can modulate the local immune microenvironment in any tissue. All specialised lymphoid tissues are densely innervated by neurons of the sympathetic nervous system and by sensory neurons containing peptide neurotransmitters. Hormones with an endocrine or paracrine mode of action also modulate the tissue microenvironment [11, 12]. This chapter will fiuther focus on the role of the ubiquitous neuropeptide somatostatin as an intersystem signalling molecule, with emphasis on the immune system.

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R. Benner (Robbert) , S.W.J. Lamberts (Steven)
Erasmus University Rotterdam
Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO)
hdl.handle.net/1765/19897
Erasmus MC: University Medical Center Rotterdam

ten Bokum, A.M. (1999, June 21). Somatostatin receptors in the immune system and immune-mediated disease. Erasmus University Rotterdam. Retrieved from http://hdl.handle.net/1765/19897