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M(1) and M(3) muscarinic receptors may play a role in the neurotoxicity of anhydroecgonine methyl ester, a cocaine pyrolysis product

The smoke of crack cocaine contains cocaine and its pyrolysis product, anhydroecgonine methyl ester (AEME). AEME possesses greater neurotoxic potential than cocaine and an additive effect when they are combined. Since atropine prevented AEME-induced neurotoxicity, it has been suggested that its toxi...

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Detalles Bibliográficos
Autores principales: Garcia, Raphael Caio Tamborelli, Dati, Livia Mendonça Munhoz, Torres, Larissa Helena, da Silva, Mariana Aguilera Alencar, Udo, Mariana Sayuri Berto, Abdalla, Fernando Maurício Francis, da Costa, José Luiz, Gorjão, Renata, Afeche, Solange Castro, Yonamine, Mauricio, Niswender, Colleen M., Conn, P. Jeffrey, Camarini, Rosana, Sandoval, Maria Regina Lopes, Marcourakis, Tania
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group 2015
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4667193/
https://www.ncbi.nlm.nih.gov/pubmed/26626425
http://dx.doi.org/10.1038/srep17555
Descripción
Sumario:The smoke of crack cocaine contains cocaine and its pyrolysis product, anhydroecgonine methyl ester (AEME). AEME possesses greater neurotoxic potential than cocaine and an additive effect when they are combined. Since atropine prevented AEME-induced neurotoxicity, it has been suggested that its toxic effects may involve the muscarinic cholinergic receptors (mAChRs). Our aim is to understand the interaction between AEME and mAChRs and how it can lead to neuronal death. Using a rat primary hippocampal cell culture, AEME was shown to cause a concentration-dependent increase on both total [(3)H]inositol phosphate and intracellular calcium, and to induce DNA fragmentation after 24 hours of exposure, in line with the activation of caspase-3 previously shown. Additionally, we assessed AEME activity at rat mAChR subtypes 1–5 heterologously expressed in Chinese Hamster Ovary cells. l-[N-methyl-(3)H]scopolamine competition binding showed a preference of AEME for the M(2) subtype; calcium mobilization tests revealed partial agonist effects at M(1) and M(3) and antagonist activity at the remaining subtypes. The selective M(1) and M(3) antagonists and the phospholipase C inhibitor, were able to prevent AEME-induced neurotoxicity, suggesting that the toxicity is due to the partial agonist effect at M(1) and M(3) mAChRs, leading to DNA fragmentation and neuronal death by apoptosis.