Abstract H2

Effects of ibogaine (IBO) on neurohormones and neurotransmitter systems in rat
S.F. Ali*^,1, G.D. Newport¹, W. Slikker¹, Jr., R..B. Rothman² and M.H. Baumann², ¹Neurochemistry Laboratory, Div. of Neurotoxicology., NCTR/FDA, Jefferson, AR, and ²ARC, NIDA, Baltimore, MD, USA

IBO is an indole alkaloid which has been proposed to treat drug addiction, however, there is concern about its potential neurotoxicity. The present study was designed to evaluate the effect of IBO on prolactin (PRO) and corticosterone (CORT) levels and the dopaminergic system. Adult CD-1 rats were dosed with 50 mg/kg IBO, ip, and sacrificed 15, 30 minutes, 1, 2 and 24 hr. later. Trunk blood was collected for hormone levels and brain was dissected for neurochemical analyses. IBO produced significant elevations in PRO levels 15 minutes after drug administration which then began to decline thereafter, and returned to control levels 2 hr after dosing. CORT levels increased 15 minutes after drug administration and continued to increase for up to 2 hr and returned to control levels 24 hr after dosing. Dopamine (DA) concentrations in striatum were decreased significantly at 30 minutes, 1 and 2 hr after drug administration, however, they returned to control levels at 24 hr. DA metabolite concentrations (DOPAC and HVA) increased in a time-dependent manner up to 2 hr. These data suggest that a single injection of IBO can produce significant elevations of PRO and CORT and depletion of DA in a time-dependent manner.