Neuronal regulators and vascular dysfunction in Raynaud's phenomenon and systemic sclerosis.

Raynaud's phenomenon (RP) results from an exaggerated cutaneous vasospastic response to cold or emotional stress. The mechanisms that lead to impaired cutaneous vascular tone are complex. The regulation of cutaneous vasoconstriction and vasodilation, involves altered sympathetic nerve activity and a host of neuronal regulators, including adrenergic and non-adrenergic, as well as REDOX signalling and other signalling such as the RhoA/ROCK pathway. This review summarises the literature concerning the regulation of vascular tone by neurohumoral factors that may be involved in RP and systemic sclerosis (SSc).