Enhancement of CO2-induced anxiety in healthy volunteers with the serotonin antagonist metergoline.
OBJECTIVE
The mechanism of action of CO2-induced anxiety is unknown and has been little studied. The authors studied healthy volunteers for the possible influence of serotonin (5-HT) on CO2-induced anxiety.


METHODS
Fourteen healthy volunteers received two vital capacity inhalations each of 35% CO2 and of air, preceded once by placebo and once by the 5-HT antagonist metergoline in a double-blind, randomized crossover design.


RESULTS
Mean National Institute of Mental Health self-rating anxiety subscale scores increased nonsignificantly after CO2 inhalation; this effect was significantly enhanced by the administration of metergoline.


CONCLUSIONS
The authors hypothesize that 5-HT may inhibit CO2-induced anxiety, a function that is lessened by metergoline.
Ben-Zion
I Z
IZ
Division of Psychiatry, Soroka Medical Center, Ben Gurion University of the Negev, Beer-sheba, Israel.
Meiri
G
G
Greenberg
B D
BD
Murphy
D L
DL
Benjamin
J
J
D000280:Administration, Inhalation; D001008:Anxiety Disorders / Q000139:chemically induced* / Q000175:diagnosis / Q000503:physiopathology; D002245:Carbon Dioxide / Q000008:administration & dosage / Q000494:pharmacology*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004357:Drug Synergism; D006801:Humans; D008711:Metergoline / Q000494:pharmacology*; D010555:Personality Inventory / Q000706:statistics & numerical data; D010919:Placebos; D012701:Serotonin / Q000502:physiology; D012702:Serotonin Antagonists / Q000494:pharmacology*
D010919:Placebos; D012702:Serotonin Antagonists; D002245:Carbon Dioxide; D008711:Metergoline; D012701:Serotonin