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Homologous upregulation of human arterial alpha-adrenergic responses by guanadrel
- Source :
- Journal of Clinical Investigation. 91:1429-1435
- Publication Year :
- 1993
- Publisher :
- American Society for Clinical Investigation, 1993.
-
Abstract
- The purpose of this study was to test the hypothesis that there is homologous upregulation of arterial alpha-adrenergic responsiveness during suppression of sympathetic nervous system (SNS) activity in humans. 10 subjects (19-28 yr) were studied during placebo and when SNS activity was suppressed by guanadrel. Changes in forearm blood flow (FABF) mediated by the intraarterial infusion of norepinephrine (NE), angiotensin II (AII), and phentolamine were measured by plethysmography. During guanadrel compared with placebo, plasma NE levels (1.28 +/- 0.09-0.85 +/- 0.06 nM; P = 0.0001) and the extra vascular NE release rate derived from [3H]NE kinetics were lower (7.1 +/- 0.7-4.0 +/- 0.2 nmol/min per m2; P = 0.0004), suggesting suppression of SNS activity. During guanadrel, there was increased sensitivity in the FABF response to NE (analysis of variance P = 0.03). In contrast, there was no difference in the FABF response to AII (analysis of variance P = 0.81), suggesting that the upregulation observed to NE was homologous. The increase in FABF during phentolamine was similar during guanadrel compared with placebo (guanadrel: 141 +/- 37 vs. placebo; 187 +/- 27% increase; P = 0.33), suggesting that there was at least partial compensation to maintain constant endogenous arterial alpha-adrenergic tone. We conclude that there is homologous upregulation of arterial alpha-adrenergic responsiveness in humans when SNS activity is suppressed by guanadrel.
- Subjects :
- Adult
Male
medicine.medical_specialty
Sympathetic nervous system
Sympathetic Nervous System
Adrenergic receptor
medicine.medical_treatment
Blood Pressure
Guanidines
Norepinephrine (medication)
Norepinephrine
Phentolamine
Guanadrel
Heart Rate
Internal medicine
Renin
Renin–angiotensin system
Humans
Infusions, Intra-Arterial
Medicine
Sympathomimetics
Dose-Response Relationship, Drug
business.industry
Angiotensin II
Arteries
General Medicine
Up-Regulation
Forearm
Kinetics
Endocrinology
medicine.anatomical_structure
Regional Blood Flow
Vasoconstriction
Female
medicine.symptom
business
Research Article
medicine.drug
Subjects
Details
- ISSN :
- 00219738
- Volume :
- 91
- Database :
- OpenAIRE
- Journal :
- Journal of Clinical Investigation
- Accession number :
- edsair.doi.dedup.....d5b0bf8144633cbde1584bec84a3f664