title: M1 and M3 muscarinic receptors may play a role in the neurotoxicity of anhydroecgonine methyl ester, a cocaine pyrolysis product.
abstract: 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 M2 subtype; calcium mobilization tests revealed partial agonist effects at M1 and M3 and antagonist activity at the remaining subtypes. The selective M1 and M3 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 M1 and M3 mAChRs, leading to DNA fragmentation and neuronal death by apoptosis.
authors.affiliation: Department of Clinical and Toxicological Analysis, School of Pharmaceutical Sciences, University of São Paulo, Av. Prof. Lineu Prestes, 580, Bl. 13B, 05508-000, São Paulo/SP, Brazil.|Institute of Environmental, Chemical and Pharmaceutical Sciences, Federal University of São Paulo, Rua São Nicolau, 210, 1° andar, 09913-030, Diadema/SP, Brazil.|Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37212, USA.|Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, 2201 West End Avenue, 1205 Light Hall, 37232-0697, Nashville/TN, USA.
authors.forename: Raphael Caio Tamborelli
authors.initials: RC
authors.lastname: Garcia
authors.affiliation: Department of Clinical and Toxicological Analysis, School of Pharmaceutical Sciences, University of São Paulo, Av. Prof. Lineu Prestes, 580, Bl. 13B, 05508-000, São Paulo/SP, Brazil.
authors.forename: Livia Mendonça Munhoz
authors.initials: LM
authors.lastname: Dati
authors.affiliation: Department of Clinical and Toxicological Analysis, School of Pharmaceutical Sciences, University of São Paulo, Av. Prof. Lineu Prestes, 580, Bl. 13B, 05508-000, São Paulo/SP, Brazil.
authors.forename: Larissa Helena
authors.initials: LH
authors.lastname: Torres
authors.affiliation: Department of Clinical and Toxicological Analysis, School of Pharmaceutical Sciences, University of São Paulo, Av. Prof. Lineu Prestes, 580, Bl. 13B, 05508-000, São Paulo/SP, Brazil.
authors.forename: Mariana Aguilera Alencar
authors.initials: MA
authors.lastname: da Silva
authors.affiliation: Department of Clinical and Toxicological Analysis, School of Pharmaceutical Sciences, University of São Paulo, Av. Prof. Lineu Prestes, 580, Bl. 13B, 05508-000, São Paulo/SP, Brazil.
authors.forename: Mariana Sayuri Berto
authors.initials: MS
authors.lastname: Udo
authors.affiliation: Laboratory of Pharmacology, Butantan Institute, Av. Vital Brasil, 1500, 05503-900, São Paulo/SP, Brazil.
authors.forename: Fernando Maurício Francis
authors.initials: FM
authors.lastname: Abdalla
authors.affiliation: Criminalistic Institute of São Paulo, Rua Moncorvo Filho, 410, 05507-060, São Paulo/SP, Brazil.
authors.forename: José Luiz
authors.initials: JL
authors.lastname: da Costa
authors.affiliation: Institute of Physical Activity Sciences and Sports, Post-Graduate Program in Human Movement Sciences, Cruzeiro do Sul University, São Paulo, Brazil.
authors.forename: Renata
authors.initials: R
authors.lastname: Gorjão
authors.affiliation: Laboratory of Pharmacology, Butantan Institute, Av. Vital Brasil, 1500, 05503-900, São Paulo/SP, Brazil.
authors.forename: Solange Castro
authors.initials: SC
authors.lastname: Afeche
authors.affiliation: Department of Clinical and Toxicological Analysis, School of Pharmaceutical Sciences, University of São Paulo, Av. Prof. Lineu Prestes, 580, Bl. 13B, 05508-000, São Paulo/SP, Brazil.
authors.forename: Mauricio
authors.initials: M
authors.lastname: Yonamine
authors.affiliation: Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37212, USA.|Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, 2201 West End Avenue, 1205 Light Hall, 37232-0697, Nashville/TN, USA.
authors.forename: Colleen M
authors.initials: CM
authors.lastname: Niswender
authors.affiliation: Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37212, USA.|Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, 2201 West End Avenue, 1205 Light Hall, 37232-0697, Nashville/TN, USA.
authors.forename: P Jeffrey
authors.initials: PJ
authors.lastname: Conn
authors.affiliation: Department of Pharmacology, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes, 1524, Prédio 1, 05508-900, São Paulo/SP, Brazil.
authors.forename: Rosana
authors.initials: R
authors.lastname: Camarini
authors.affiliation: Laboratory of Pharmacology, Butantan Institute, Av. Vital Brasil, 1500, 05503-900, São Paulo/SP, Brazil.
authors.forename: Maria Regina Lopes
authors.initials: MR
authors.lastname: Sandoval
authors.affiliation: Department of Clinical and Toxicological Analysis, School of Pharmaceutical Sciences, University of São Paulo, Av. Prof. Lineu Prestes, 580, Bl. 13B, 05508-000, São Paulo/SP, Brazil.
authors.forename: Tania
authors.initials: T
authors.lastname: Marcourakis
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D016466:CHO Cells; D003042:Cocaine / Q000031:analogs & derivatives* / Q000633:toxicity; D006224:Cricetinae; D003412:Cricetulus; D053938:DNA Fragmentation / Q000187:drug effects; D005260:Female; D006624:Hippocampus / Q000378:metabolism* / Q000473:pathology; D020258:Neurotoxicity Syndromes / Q000378:metabolism* / Q000473:pathology; D009498:Neurotoxins / Q000633:toxicity*; D051381:Rats; D043643:Receptor, Muscarinic M1 / Q000378:metabolism*; D043587:Receptor, Muscarinic M3 / Q000378:metabolism*; D013997:Time Factors
chemical_list: D009498:Neurotoxins; D043643:Receptor, Muscarinic M1; D043587:Receptor, Muscarinic M3; C068464:anhydroecgonine methyl ester; D003042:Cocaine