Cold Hypersensitivity in Raynaud's Phenomenon
We have sought evidence that local cooling enhances the adrenergic neurotransmitter mechanism in resistance vessels in the hands of subjects with Raynaud's phenomenon. The method used was to examine the magnitude and time-course of the reflex vasoconstriction in the hand which follows application of ice to the neck. One hand of each subject was kept at 26°C and the other at 36°C, while the general thermal environment was varied. Enhancement was found in three groups of subjects: those with idiopathic, early age-onset, Raynaud's disease; those with Raynaud's phenomenon of late age-onset; and those with systemic scleroderma. It was absent in normal subjects. The effect could not be accounted for by structural abnormalities of resistance vessels, blood abnormalities, nor by interference with norepinephrine reuptake or dissipation at the neuro-effector junction.
- Received February 17, 1971.
- Accepted April 12, 1971.
- © 1971 American Heart Association, Inc.