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Expression of NR1/NR2B N ‐Methyl‐ d ‐Aspartate Receptors Enhances Heroin Toxicity in HEK293 Cells
Author(s) -
DOMINGUES ANTÓNIO,
CUNHA OLIVEIRA TERESA,
LAÇO MÁRIO L. N.,
MACEDO TICE R. A.,
OLIVEIRA CATARINA R.,
REGO A. CRISTINA
Publication year - 2006
Publication title -
annals of the new york academy of sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.712
H-Index - 248
eISSN - 1749-6632
pISSN - 0077-8923
DOI - 10.1196/annals.1369.046
Subject(s) - nmda receptor , transfection , hek 293 cells , viability assay , neurotoxicity , receptor , glutamate receptor , chemistry , pharmacology , intracellular , microbiology and biotechnology , apoptosis , toxicity , biology , biochemistry , organic chemistry , gene
Repeated use of drugs of abuse, namely opiates, has been shown to affect glutamate‐releasing neurons. Moreover, blockade of N ‐methyl‐D‐aspartate (NMDA) receptors (NMDAR) prevents cell death by apoptosis induced by morphine, a heroin metabolite. Thus, in this article we investigated the involvement of different NMDAR subunits in heroin cytotoxicity. Human embryonic kidney (HEK293)cells, which do not express native NMDAR, were transfected with NR1/NR2A or NR1/NR2B subunits. As a control, cells were transfected with NR1 alone, which does not form functional channels. Incubation with heroin for 24 h induced a dose‐dependent decrease in cell viability both in NR1‐transfected and nontransfected cells. The loss of membrane integrity induced by heroin was more evident in cells transfected with NR1/NR2B than in cells transfected with NR1 alone or NR1/NR2A. This decrease in cell viability was blocked by MK‐801, a selective and noncompetitive antagonist of NMDAR. Nevertheless, no significant changes in intracellular adenosine 5′‐triphosphate (ATP) were observed in cells treated with heroin. These data implicate NR2B‐composed NMDAR as important mediators of heroin neurotoxicity.