Induced panic attacks shift gamma-aminobutyric acid type A receptor modulatory neuroactive steroid composition in patients with panic disorder: preliminary results.
BACKGROUND
Certain metabolites of progesterone such as 3alpha,5alpha-tetrahydroprogesterone (3alpha,5alpha-THP; allopregnanolone) and 3alpha,5beta-THP (pregnanolone) are potent, positive allosteric modulators of gamma-aminobutyric acid type A receptors. Although animal studies suggest anxiolytic properties of these endogenous modulators of central nervous excitability, no clinical data indicate whether they are also involved in the pathophysiology of anxiety disorders and panic attacks.


METHODS
We quantified the concentrations of 3alpha,5alpha-THP, 3alpha,5beta-THP, the isomer 3beta,5alpha-THP, and their precursors in the plasma of 10 patients with panic disorder and matched control subjects during panic attacks induced by means of sodium lactate and cholecystokinin tetrapeptide administration, using a highly sensitive gas chromatography-mass spectrometry analysis.


RESULTS
Panic attacks induced by sodium lactate and cholecystokinin tetrapeptide in patients with panic disorder were accompanied by pronounced decreases in the concentrations of 3alpha,5alpha-THP and 3alpha,5beta-THP and a concomitant increase in the concentrations of the functional antagonistic isomer 3beta,5alpha-THP, findings that are compatible with a decreased gamma-aminobutyric acid-ergic tone. No changes in neuroactive steroid concentrations were observed after placebo administration in patients with panic disorder or after placebo, sodium lactate, or cholecystokinin tetrapeptide administration in controls.


CONCLUSIONS
The association between changes in plasma neuroactive steroid concentrations and experimentally induced panic attacks and the well-documented pharmacological properties of these compounds as gamma-aminobutyric acid type A receptor modulators suggest that neuroactive steroids may play a role in the pathophysiology of panic attacks in patients with panic disorder.
Ströhle
Andreas
A
Max Planck Institute of Psychiatry, Munich, Germany. andreas.stroehle@charite.de
Romeo
Elena
E
di Michele
Flavia
F
Pasini
Augusto
A
Hermann
Bettina
B
Gajewsky
Gisela
G
Holsboer
Florian
F
Rupprecht
Rainer
R
D000328:Adult; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D012739:Gonadal Steroid Hormones / Q000097:blood* / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D016584:Panic Disorder / Q000097:blood* / Q000139:chemically induced* / Q000503:physiopathology; D010919:Placebos; D011280:Pregnanolone / Q000097:blood* / Q000502:physiology; D011963:Receptors, GABA-A / Q000187:drug effects* / Q000502:physiology; D019354:Sodium Lactate / Q000008:administration & dosage; D013758:Tetragastrin / Q000008:administration & dosage
D012739:Gonadal Steroid Hormones; D010919:Placebos; D011963:Receptors, GABA-A; D013758:Tetragastrin; D011280:Pregnanolone; D019354:Sodium Lactate