Altered norepinephrine metabolism in Shapiro's syndrome
J. A. Sanfield, O. A. Linares, D. D. Cahalan, J. M. Forrester, J. B. Halter and S. G. Rosen
Department of Internal Medicine, University of Michigan, Ann Arbor.
We studied a 66-year-old woman with spontaneous periodic hypothermia
(Shapiro's syndrome) to determine the mechanisms that result in increased
plasma norepinephrine (NE) levels. In comparison with age-matched control
subjects, compartmental analysis of NE kinetics revealed an increased NE
release rate into the extravascular compartment and decreases in NE
clearance and volume of distribution of NE in the intravascular
compartment. Clonidine therapy was associated with an initial dramatic
decrease in the frequency of diaphoretic episodes as well as with a fall in
NE release rate and increases in NE clearance and volume of distribution.
We conclude that increased NE release and decreased plasma NE clearance
result in elevated plasma NE levels in Shapiro's syndrome. Clonidine, which
was associated with changes in NE kinetics, may provide effective treatment
for this disorder.