Dermal microdialysis provides evidence for hypersensitivity to noradrenaline in patients with familial dysautonomia.
OBJECTIVE
To use the technique of dermal microdialysis to examine sensitivity of skin vessels to noradrenaline (NA) in patients with familial dysautonomia (FD) and in healthy controls.


METHODS
In 14 patients with FD and 12 healthy controls, plasma extravasation, local laser Doppler blood flow, and skin blanching were observed before, during, and after application of 10(-6) M NA through a microdialysis membrane, located intradermally in the skin of the lower leg.


RESULTS
Maximum local vasoconstriction measured by laser Doppler blood flow did not differ between patients with FD and controls. In contrast, patients with FD had an earlier onset of vasoconstriction (p = 0.02). Moreover, reaction to NA was more prominent and prolonged in FD, shown by a larger zone of skin blanching around the microdialysis membrane (p < 0.001) and delayed reduction of the protein content in the dialysate after termination of NA application (p = 0.03).


CONCLUSIONS
These data support the hypothesis that peripheral blood vessels of patients with FD show a denervation hypersensitivity to catecholamines. This may be one mechanism contributing to the major hypertension that frequently occurs during "dysautonomic crises" in FD.
Neurologische Klinik, Universität Erlangen-Nürnberg, Schwabachanlage 6, 91054 Erlangen, Germany.
A
A
Bickel
F B
FB
Axelrod
M
M
Schmelz
H
H
Marthol
M J
MJ
Hilz
D000279:Administration, Cutaneous; D000293:Adolescent; D000328:Adult; D001783:Blood Flow Velocity / Q000502:physiology; D004342:Drug Hypersensitivity / Q000175:diagnosis / Q000209:etiology*; D004402:Dysautonomia, Familial / Q000628:therapy*; D004867:Equipment Design; D005260:Female; D006801:Humans; D017078:Laser-Doppler Flowmetry; D007866:Leg / Q000098:blood supply; D008297:Male; D008567:Membranes, Artificial; D017551:Microdialysis / Q000295:instrumentation*; D009638:Norepinephrine / Q000008:administration & dosage / Q000009:adverse effects*; D011506:Proteins / Q000378:metabolism; D012867:Skin / Q000098:blood supply / Q000378:metabolism; D014661:Vasoconstriction
D008567:Membranes, Artificial; D011506:Proteins; D009638:Norepinephrine