Decreased sensitivity to alpha-adrenergic stimulation in hypothyroid patients

Details

Serval ID
serval:BIB_32F6F705480B
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Decreased sensitivity to alpha-adrenergic stimulation in hypothyroid patients
Journal
Journal of Clinical Endocrinology and Metabolism
Author(s)
Polikar  R., Kennedy  B., Ziegler  M., Smith  J., Nicod  P.
ISSN
0021-972X (Print)
Publication state
Published
Issued date
06/1990
Volume
70
Number
6
Pages
1761-4
Notes
Journal Article
Research Support, U.S. Gov't, P.H.S. --- Old month value: Jun
Abstract
Nine hypothyroid patients had blood pressure and pulse rate responses to the alpha-adrenergic agonist phenylephrine measured before [T4 index, 45.045 +/- 9.009 nmol/L (mean +/- SEM); TSH, 57.1 +/- 23.6 mU/L] and after 4 +/- 0.5 months of thyroid replacement therapy (T4 index, 141.570 +/- 29.601 nmol/L; TSH, 2.6 +/- 1.0 mU/L). Hypothyroid patients had a smaller blood pressure increment and heart rate decrement at both 66.7 and 100 micrograms/min infusion rates of phenylephrine. Furthermore, the slope of the dose-response curves for systolic (2.06 +/- 0.22 vs. 1.32 +/- 0.19; P less than 0.01) and diastolic (1.04 +/- 0.18 vs. 0.62 +/- 0.08; P less than 0.01) blood pressures were significantly greater after thyroid replacement therapy. Pulse rate changes remained proportional to blood pressure changes in hypothyroid patients, so there was no change in baroreflex sensitivity. Plasma norepinephrine levels were higher before than after thyroid replacement (2.41 +/- 0.28 vs. 1.82 +/- 0.29 nmol/L, respectively; P less than 0.01). Thus, hypothyroid patients have diminished pressor sensitivity to an alpha-adrenergic agonist and increased plasma levels of the alpha-adrenergic neutrotransmitter norepinephrine.
Keywords
Adult Aged Blood Pressure/drug effects Dose-Response Relationship, Drug Epinephrine/blood Female Heart Rate/drug effects Humans Hypothyroidism/*physiopathology Male Middle Aged Norepinephrine/blood Phenylephrine/*pharmacology Thyroid Gland/drug effects/metabolism Thyroxine/pharmacology Triiodothyronine/metabolism
Pubmed
Web of science
Create date
25/01/2008 14:00
Last modification date
20/08/2019 13:18
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