MAPS: Neurotensin and ibogaine - cocaine responses

[LotsofHS@xxxxxxx]

Dear list,

The following paper that just showed on medline represents data in a new area
of ibogaine research.

Howard Lotsof
=======================================================

Brain Res 1999 Feb 6;818(1):96-104
 
Differential responses by neurotensin systems in extrapyramidal and limbic 
structures to ibogaine and cocaine.

Alburges ME, Hanson GR
Department of Pharmacology and Toxicology, College of Pharmacy, University of
Utah, 112 Skaggs 
Hall, Salt Lake City, UT 84112, USA
 
[Record supplied by publisher]
Ibogaine (Endabuse) is a psychoactive indole alkaloid found in the West
African shrub, Tabernanthe 
iboga. This drug interrupts cocaine and amphetamine abuse and has been
proposed for treatment of 
addiction to these stimulants. However, the mechanism of action that explains
its pharmacological 
properties is unclear. Since previous studies demonstrated differential
effects of psychotomimetic 
drugs (cocaine and methamphetamine) on neuropeptides such as neurotensin (NT),
the present study 
was designed to determine: (1) the effects of ibogaine on striatal, nigral,
cortical, and accumbens 
neurotensin-like immunoreactivity (NTLI); (2) the effects of selective
dopamine antagonists on 
ibogaine-induced changes in NT concentrations in these brain areas; and (3)
the effects of ibogaine 
pretreatment on cocaine-induced changes in striatal, nigral, cortical and
accumbens NTLI content. 
Ibogaine treatments profoundly affected NT systems by increasing striatal,
nigral, and accumbens 
NTLI content 12 h after the last drug administration. In contrast, NTLI
concentrations were not 
significantly increased in the frontal cortex after ibogaine treatment. The
ibogaine-induced increases in 
NTLI in striatum, nucleus accumbens and substantia nigra were blocked by
coadministration of the s
elective D1 receptor antagonist, SCH 23390. The D2 receptor antagonist,
eticlopride, blocked the 
ibogaine-induced increase in nigral NTLI, but not in striatum and nucleus
accumbens. Ibogaine 
pretreatment significantly blocked the striatal and nigral increases of NTLI
resulting from a single 
cocaine administration. Whereas many of the responses by NT systems to
ibogaine resembled those 
which occur after cocaine, there were also some important differences. These
data suggest that NT 
may contribute to an interaction between ibogaine and the DA system and may
participate in the 
pharmacological actions of this drug. Copyright 1999 Elsevier Science B.V

http://www.ibogaine.org
http://www.ibogaine.desk.nl

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