Neuroactive steroid changes in response to challenge with the panicogenic agent pentagastrin.

Background: Female hormones and female hormone derivatives, including neuroactive steroids (NASs) have been suspected to play a role in the pathophysiology of panic disorder (PD). The panicogenic agent CO(2) has been shown to induce a delayed release of NASs in both brain and plasma of rats. In the present study, we measured NASs plasma levels in response to challenge with another panicogenic agent, pentagastrin, and assessed the effect of ethynil estradiol (EE) pretreatment.

Methods: A double-blind cross-over placebo-controlled design with randomization of the order of a three day pretreatment of EE (50 microg/day) or placebo was used to assess the effect of a 30 microg iv bolus injection of pentagastrin on the release of allopregnanolone (ALLO) and dehydroepiandrosterone (DHEA) into plasma in 15 male PD patients and 10 male healthy volunteers (HV).

Results: After pentagastrin challenge there was a significant release of DHEA and a trend for the release of ALLO. EE pretreatment did not affect the pentagastrin-induced panic response or NAS release.

Conclusions: Pentagastrin induced release of NASs into plasma, the purpose of which remains to be determined.