Identification of mu- and kappa-opioid receptors as potential targets to regulate parasympathetic, sympathetic, and sensory neurons within rat intracardiac ganglia
| Autor: | Jörn Schäper, Michael Schäfer, Helmut Habazettl, Hashim Abdul-Khaliq, Wei Huang, Sascha Treskatsch, Shaaban A. Mousa, Mohammed Shaqura |
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| Rok vydání: | 2010 |
| Předmět: |
Male
medicine.medical_specialty Sensory Receptor Cells Receptors Opioid mu Substance P Calcitonin gene-related peptide Biology Immunofluorescence κ-opioid receptor chemistry.chemical_compound Internal medicine Vesicular acetylcholine transporter medicine Animals RNA Messenger Rats Wistar Receptor medicine.diagnostic_test Tyrosine hydroxylase General Neuroscience Receptors Opioid kappa Heart Immunohistochemistry Parasympathetic Fibers Postganglionic Rats Endocrinology nervous system chemistry Opioid Adrenergic Fibers medicine.drug |
| Zdroj: | The Journal of comparative neurology. 518(18) |
| ISSN: | 1096-9861 |
| Popis: | Recent interest has been focused on the opioid regulation of heart performance; however, specific allocation of opioid receptors to the parasympathetic, sympathetic, and sensory innervations of the heart is scarce. Therefore, the present study aimed to characterize such specific target sites for opioids in intracardiac ganglia, which act as a complex network for the integration of the heart's neuronal in- and output. Tissue samples from rat heart atria were subjected to RT-PCR, Western blot, radioligand-binding, and double immunofluorescence confocal analysis of mu (M)- and kappa (K)-opioid receptors (ORs) with the neuronal markers vesicular acetylcholine transporter (VAChT), tyrosine hydroxylase (TH), calcitonin gene-related peptide (CGRP), and substance P (SP). Our results demonstrated MOR- and KOR-specific mRNA, receptor protein, and selective membrane ligand binding. By using immunofluorescence confocal microscopy, MOR and KOR immunoreactivity were colocalized with VAChT in large-diameter parasympathetic principal neurons, with TH-immunoreactive small intensely fluorescent (SIF) cells, and on nearby TH-IR varicose terminals. In addition, MOR and KOR immunoreactivity were identified on CGRP- and SP-IR sensory neurons throughout intracardiac ganglia and atrial myocardium. Our findings show that MOR and KOR are expressed as mRNA and translated into specific receptor proteins on cardiac parasympathetic, sympathetic, and sensory neurons as potential binding sites for opioids. Thus, they may well play a role within the complex network for the integration of the heart's neuronal in- and output. |
| Databáze: | OpenAIRE |
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