Salivary alpha-amylase levels after yohimbine challenge in healthy men.
BACKGROUND
We and others have previously shown that standardized psychosocial stress significantly increases salivary alpha-amylase (sAA), but it remains unclear whether sAA reflects autonomic nervous system activation.


OBJECTIVE
The aim of this study was to assess cardiovascular effects and sAA and catecholamine secretion after iv injection of yohimbine.


METHODS
We conducted a randomized double-blind placebo-controlled study at an academic research unit.


METHODS
Thirteen healthy males (aged 20-28 yr) were examined.


METHODS
Participants received iv injection of yohimbine (0.4 microg/kg) or placebo (0.9% NaCl).


METHODS
Eight saliva and blood samples were taken before and after injection for the assessment of salivary flow rate and sAA and catecholamine concentrations. In addition, blood pressure, mood, and anxiety were assessed repeatedly.


RESULTS
Yohimbine induced increases of sAA activity and output in comparison to placebo (P = 0.034). Blood pressure (P < 0.001), salivary flow rate (P = 0.007), and catecholamines (P < 0.001) were also significantly increased. No significant correlations between alpha-amylase parameters and catecholamines were observed.


CONCLUSIONS
The results indicate that yohimbine administration activates not only autonomic parameters but also sAA via adrenergic mechanisms, suggesting that sAA might be an indirect indicator of the central sympathetic system.
Ehlert
Ulrike
U
Department of Clinical Psychology and Psychotherapy, University of Zurich, Binzmuehlestrasse 14, CH-8050 Zurich, Switzerland. ehlert@psychologie.unizh.ch
Erni
Katja
K
Hebisch
Gundula
G
Nater
Urs
U
D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000328:Adult; D000339:Affect / Q000187:drug effects; D001007:Anxiety / Q000201:enzymology; D001794:Blood Pressure / Q000187:drug effects; D004311:Double-Blind Method; D004837:Epinephrine / Q000097:blood; D006801:Humans; D008297:Male; D010919:Placebos; D012463:Saliva / Q000187:drug effects* / Q000201:enzymology*; D013315:Stress, Psychological / Q000201:enzymology; D015016:Yohimbine / Q000494:pharmacology*; D000516:alpha-Amylases / Q000032:analysis*
D000317:Adrenergic alpha-Antagonists; D010919:Placebos; D015016:Yohimbine; D000516:alpha-Amylases; D004837:Epinephrine