Analysis of vasospasm in hand arteries by in vitro pharmacology, hand angiography and finger plethysmography.

1. The distribution of sympathetic nerves in hand arteries and veins from 18 normal subjects was studied by microscopy according to the Falck-Hillarp histofluorescence method for the cellular visualization of cathecholamines and by quantitative analysis of noradrenaline with a radioenzymatic method. Segments of hand arteries and veins were tested in vitro for the vasomotor effect of sympathomimetic agonists. 2. Fluorescence microscopy revealed a plexus of noradrenaline-containing nerve fibres surrounding both arteries and veins. The concentration of noradrenaline in the walls were 4.5-4.7 ng/mg protein. The relative agonist potency was characteristic for alpha-receptors. Phentolamine produced parallel shift of the dose-response curves both for arteries and veins. 3. Finger plethysmography with local cold provocation down to 10 degrees C was performed in the patients with traumatic vasospastic disease before and after inhibition of the sympathetic nervous system by body warming and orally administered alcohol. Four patients had undisturbed circulation, as revealed by the ratio between the systolic blood pressure in the arm and in the finger in conjunction with cold provocation tests. 13 patients had vasospasm of varying degrees, and 3 patients suffered from organic stenosis. 4. Hand angiography was performed before and after local cold provocation. The patients with organic stenosis did not show vasodilatation after 4-6 mg phentolamine injection. Patients with true vasospasm responded, in addition, with efficient vasodilatation 15 min after reserpine injection, which also abolished the cold-induced vasospasm.