01 September 2006
Cholinergic regulation of endogenous morphine release from lobster nerve cord
Wei Zhu, Kirk J Mantione, Federico M Casares, Melinda H Sheehan, Richard M. Kream, George B StefanoMed Sci Monit 2006; 12(9): BR295-301 :: ID: 455228
Abstract
Background:Invertebrate nervous systems are regulated by G-coupled protein receptors, chemical transporters, and ion channels responsive to established drugs of abuse including opiates, alcohol, psychostimulants, and nicotine. Thus, invertebrate nervous tissue preparations can be used as predictive model systems by which to evaluate underlying pharmacological mechanisms of addictive processes.
Material/Methods: Ex vivo pharmacological trials were used to determine the comparative effects of the nicotinic agonists and antagonists on the evoked release of labeled morphine from H. americanus nerve cord. The intrinsically low basal levels of endogenous morphine required that we utilize an ex vivo model system involving pre-labeling of intracellular opiate alkaloid pools with high specific activity [sup]125[/sup]I labeled morphine.
Results: Both nicotine and epibatidine promoted evoked release of [sup]125[/sup]I labeled morphine that is selectively linked to activation of invertebrate nicotinic receptors based on pharmacological inhibition by α bungarotoxin (α-BuTx). Epibatidine promoted release at concentrations 2–3 orders of magnitude higher than nicotine. Co-administration of nicotine (60 nM) and the pre-junctional ganglionic nicotinic antagonist hexamethonium (1 µM) produced a marked potentiation of [sup]125[/sup]I labeled morphine release; a pharmacological effect also observed for epibatidine (35 µM) co-administered with the competitive nicotinic antagonist chlorisondamine at 1 µM. The stimulatory effects of ethanol to promote enhanced release of endogenous morphine were not affected by co-administration of α-BuTx at 1 µM.
Conclusions: The stimulatory effects of nicotine on cellular expression and release of endogenous morphine occurs via specific α-BuTx sensitive receptors, suggesting a novel mechanism underlying the reinforcing and addictive properties of nicotine via endogenous morphine.
Keywords: Bicyclo Compounds, Heterocyclic - pharmacology, Bungarotoxins - pharmacology, Ethanol - pharmacology, Ganglia, Invertebrate - metabolism, Hexamethonium - pharmacology, Morphine - metabolism, Nephropidae - metabolism, Nicotine - pharmacology, Nicotinic Agonists - pharmacology, Nicotinic Antagonists - pharmacology, Pyridines - pharmacology, Receptors, Nicotinic - physiology, alpha7 Nicotinic Acetylcholine Receptor
Editorial
01 April 2025 : Editorial
Editorial: Rapid Testing for the Avian Influenza A(H5N1) Virus is Urgently Required as Infections in Poultry and Dairy Cows are on the Rise, and so is Transmission to HumansDOI: 10.12659/MSM.949109
Med Sci Monit 2025; 31:e949109
In Press
Clinical Research
Longitudinal Evaluation of Metabolic Benefits of Inactivated COVID-19 Vaccination in Diabetic Patients in T...Med Sci Monit In Press; DOI: 10.12659/MSM.947450
Clinical Research
Impact of Voltage Level on Hospitalization and Mortality in Electrical Injury Cases: A Retrospective Analys...Med Sci Monit In Press; DOI: 10.12659/MSM.947675
Clinical Research
Comparative Study of Plantar Load and Foot Posture Characteristics in Male Elite Squash Players and Non-Ath...Med Sci Monit In Press; DOI: 10.12659/MSM.947828
Clinical Research
Dental Students’ Opinions on Use of Artificial Intelligence: A Survey StudyMed Sci Monit In Press; DOI: 10.12659/MSM.947658
Most Viewed Current Articles
17 Jan 2024 : Review article 8,071,874
Vaccination Guidelines for Pregnant Women: Addressing COVID-19 and the Omicron VariantDOI :10.12659/MSM.942799
Med Sci Monit 2024; 30:e942799
16 May 2023 : Clinical Research 702,992
Electrophysiological Testing for an Auditory Processing Disorder and Reading Performance in 54 School Stude...DOI :10.12659/MSM.940387
Med Sci Monit 2023; 29:e940387
01 Mar 2024 : Editorial 30,169
Editorial: First Regulatory Approvals for CRISPR-Cas9 Therapeutic Gene Editing for Sickle Cell Disease and ...DOI :10.12659/MSM.944204
Med Sci Monit 2024; 30:e944204
28 Jan 2024 : Review article 24,060
A Review of IgA Vasculitis (Henoch-Schönlein Purpura) Past, Present, and FutureDOI :10.12659/MSM.943912
Med Sci Monit 2024; 30:e943912