Pentagastrin test for anxiety--psychophysiology and personality.
BACKGROUND
CCK(B) receptor agonists such as pentagastrin or CCK(4) have anxiogenic panic-like effects in humans. Our previous findings are in agreement with a relationship between C-peptide plasma levels (as a measure of insulin release) and sensitivity to psychotropic activation by CCK(B) receptor stimulation.


OBJECTIVE
Our present aim was to study the transient humoral, physiological and psychotropic effects of pentagastrin bolus injection and whether personality might affect the outcome.


METHODS
Pentagastrin was given in bolus i.v. injections to healthy volunteers at increasing doses (0.003, 0.012, 0.05 and 0.2 microg/kg). Physiological parameters were recorded before and during each pentagastrin challenge and humoral variables described previously were included in the analyzes. Subjects rated the discomfort following pentagastrin administration on the state anxiety and discomfort scale (SADS). The Karolinska scale of personality (KSP), anxiety sensitivity index (ASI) and Hamilton anxiety scale (HAS) were used to characterize the subjects before the test.


RESULTS
Galvanic skin response (GSR) and heart rate (HR) were significantly increased within 1 min following 0.2 microg/kg pentagastrin, the GSR increase correlating negatively to the C-peptide increase and positively to ratings on SADS. Even the lower dose (0.05 microg/kg pentagastrin) induced a significant increase in GSR. ASI measures correlated weakly to the increase in ratings on SADS following 0.05 microg/kg and 0.2 microg/kg pentagastrin.


CONCLUSIONS
We found correlations between psychophysiology, humoral response and subjective ratings following pentagastrin administration. CCK(B) receptor stimulation might reveal phenotype properties predictive of anxiety-related traits, measurable through serum levels of C-peptide. Furthermore, our results support the predictive value of ASI for fearfulness.
Radu
Diana
D
Department of Clinical Neuroscience, Section of Psychiatry, Karolinska Institutet, 171 76 Stockholm, Sweden. diana.radu@cns.ki.se
Ahlin
Arne
A
Svanborg
Pär
P
Lindefors
Nils
N
D000328:Adult; D001007:Anxiety / Q000139:chemically induced* / Q000523:psychology; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D008297:Male; D010418:Pentagastrin / Q000494:pharmacology*; D010551:Personality; D043887:Receptor, Cholecystokinin B; D011949:Receptors, Cholecystokinin / Q000187:drug effects; D012867:Skin / Q000187:drug effects
D043887:Receptor, Cholecystokinin B; D011949:Receptors, Cholecystokinin; D010418:Pentagastrin