ABSTRACT
Ne u ro p e p tid e s a re s y n th e s is e d a n d released by several nerve types. However, it is now realised tha t C and Аб fibres can function as vasodilator neurones as a con sequence o f their ability to release neuropep tides, o f w hich calcitonin gene-related pep tid e (C G R P ) is o f m a jo r im p o r ta n c e . Sensory C-fibres are unm yelinated and often referred to as capsaicin-sensitive. Some Аб fibres also show sensitivity to capsaicin. C ap saicin acts via a specific b inding site on sen sory nerve to excite and then desensitise and, in som e cases, destroy sensory nerves.1 The trea tm en t o f neonatal rats w ith neurotoxic doses o f capsaicin leads to a depletion o f n e u ro p e p tid e s fro m cap sa ic in -sen sitiv e nerves and the appearance o f cu taneous lesions.2,3 This suggests th a t neuropeptides play a physiological role in the m aintenance o f a healthy skin. Indeed there is evidence from the study o f diseases th a t affect the peripheral vasculature (e.g. R aynauds phe nom enon and diabetes) tha t a depletion o f neuropeptides is associated w ith the vascu la r an d c u tan e o u s p ro b lem s w h ich are observed.
