Neurotoxicity of heroin-cocaine combinations in rat cortical neurons

• Type: Article in International Scientific Journal
• Date: 2010

Authors

cunha-oliveira, teresa (Author) Other; rego, a. cristina (Author) Other; garrido, jorge (Author) Other; borges, fernanda (Author) FCUP; macedo, tice (Author) Other; oliveira, catarina r. (Author) Other

Journal

Title: Toxicology

Vol. 276

Pages: 11-17

ISSN: 0300-483X

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 58 Citations

Scopus - 61 Citations

Scientific classification

FOS: Natural sciences > Chemical sciences

Other information

Authenticus ID: P-003-2RE

DOI: 10.1016/j.tox.2010.06.009

Abstract (EN): Cocaine and heroin are frequently co-abused by humans, in a combination known as speedball. Recently. chemical interactions between heroin (Her) or its metabolite morphine (Mor) and cocaine (Coc) were described, resulting in the formation of strong adducts. In this work, we evaluated whether combinations of Coc and Her affect the neurotoxicity of these drugs, using rat cortical neurons incubated with Coc, Her, Her followed by Coc (Her + Coc) and Her plus Coc (Her:Coc, 1:1). Neurons exposed to Her, Her + Coc and Her:Coc exhibited a decrease in cell viability, which was more pronounced in neurons exposed to Her and Her + Coc, in comparison with neurons exposed to the mixture (Her:Coc). Cells exposed to the mixture showed increased intracellular calcium and mitochondrial dysfunction, as determined by a decrease in intracellular ATP levels and in mitochondrial membrane potential, displaying both apoptotic and necrotic characteristics. Conversely, a major increase in cytochrome c release, caspase 3-dependent apoptosis, and decreased metabolic neuronal viability were observed upon sequential exposure to Her and Coc. The data show that drug combinations potentiate cortical neurotoxicity and that the mode of co-exposure changes cellular death pathways activated by the drugs, strongly suggesting that chemical interactions occurring in Her:Coc, such as adduct formation, shift cell death mechanisms towards necrosis. Since impairment of the prefrontal cortex is involved in the loss of impulse control observed in drug addicts, the data presented here may contribute to explain the increase in treatment failure observed in speedball abusers. (C) 2010 Elsevier Ireland Ltd. All rights reserved.

Language: English

Type (Professor's evaluation): Scientific