Abstract | BACKGROUND: METHODS: Patients with neurogenic OH (PD + OH; N = 35), MSA (N = 41), and PAF (N = 12) received iv trimethaphan (TRI), which inhibits sympathetic nerve traffic, or yohimbine (YOH), which stimulates sympathetic traffic. Dependent measures included blood pressure, plasma norepinephrine (NE) levels, and interventricular septal myocardial radioactivity after iv injection of the sympathoneural imaging agent, 6-[F]fluorodopamine. RESULTS: The PD + OH and PAF groups had smaller pressor responses to YOH (12 +/- 8 and 13 +/- 1 mm Hg) and depressor responses to TRI (-14 +/- 8 and -17 +/- 7 mm Hg) than did the MSA group (43 +/- 8 mm Hg, -57 +/- 8 mm Hg; P = 0.01, P = 0.03). The PD + OH and MSA groups did not differ in NE responses to YOH and TRI. The depressor response to TRI, the pressor response to YOH, and the blood pressure difference between YOH and TRI all correlated positively with myocardial 6-[F]fluorodopamine-derived radioactivity. CONCLUSIONS: The PD + OH resembles PAF and differs from MSA in hemodynamic responses to drugs that alter NE release from sympathetic nerves. The results fit with sympathetic noradrenergic denervation in PD + OH and PAF but not in MSA.
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Authors | Yehonatan Sharabi, Basil Eldadah, Sheng-Ting Li, Rhaguveer Dendi, Sandra Pechnik, Courtney Holmes, David S Goldstein |
Journal | Clinical neuropharmacology
(Clin Neuropharmacol)
2006 May-Jun
Vol. 29
Issue 3
Pg. 97-105
ISSN: 0362-5664 [Print] United States |
PMID | 16772807
(Publication Type: Clinical Trial, Comparative Study, Journal Article)
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Chemical References |
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Topics |
- Blood Pressure
(drug effects, physiology)
- Female
- Humans
- Hypotension, Orthostatic
(diagnosis, metabolism)
- Male
- Middle Aged
- Multiple System Atrophy
(diagnosis, metabolism)
- Parkinson Disease
(diagnosis, metabolism)
- Shy-Drager Syndrome
(diagnosis, metabolism)
- Trimethaphan
(pharmacology)
- Ventricular Function, Left
(drug effects, physiology)
- Yohimbine
(pharmacology)
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