Vasomotor functions of skin microcirculation in vasospastic Raynaud's phenomena

An overview of our recent studies is given. The following subjects were investigated: Women with primary Raynaud's phenomenon (PRP) and their female controls (FC); vibration exposed workers without (HAV) and with vibration-induced white finger (VWF); men with chemotherapy-induced Raynaud's phenomenon (CRP) and men with similar treatment but without finger symptoms (CVB); and male controls (MC). All three forms of Raynaud's phenomenon (RP) had a vasospastic and not an obstructive disease. The relative capillary blood flow rate in the skin of the finger was measured by the local 133Xenon washout technique during three different postural stimuli before and after hand vibration and furthermore during hand vibration. The main results indicate a hyperreactivity of the central sympathetic nervous system in all three types of vasospastic RP, which may be responsible for episodes of RP; a dysfunction of the peripheral sensory nerve fibers in VWF; a chemotherapy-induced prolonged vascular-toxic effect only on the terminal arterioles regardless of finger symptoms; and an only transitory mechanical effect of hand vibration on the arteriolar vasomotor function. The applied quantitative mapping of the function levels of the different elements involved in sympathetic vasoconstriction may be valuable in the evaluation of the pathophysiological components in other forms of RP.