δ-Opioid receptors: Pivotal role in intermittent hypoxia-augmentation of cardiac parasympathetic control and plasticity
| Autor: | Robert T. Mallet, Darice Yoshishige, Mathew A. Barlow, James L. Caffrey, Arthur G. Williams, Juan Estrada, H. Fred Downey |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
medicine.medical_specialty Adrenergic receptor Enkephalin Methionine Microdialysis Narcotic Antagonists Adrenergic Article Norepinephrine 03 medical and health sciences Cellular and Molecular Neuroscience Dogs 0302 clinical medicine Naltrindole Receptors Opioid delta Internal medicine medicine Animals Heart Atria Hypoxia Sinoatrial Node Opioidergic Neuronal Plasticity Endocrine and Autonomic Systems Sinoatrial node business.industry Vagus Nerve Intermittent hypoxia Naltrexone Vagus nerve 030104 developmental biology medicine.anatomical_structure Endocrinology Cholinergic Neurology (clinical) business 030217 neurology & neurosurgery medicine.drug |
| Zdroj: | Autonomic Neuroscience. 198:38-49 |
| ISSN: | 1566-0702 |
| DOI: | 10.1016/j.autneu.2016.07.007 |
| Popis: | Intermittent hypoxia training (IHT) produces robust myocardial protection against ischemia-reperfusion induced infarction and arrhythmias. Blockade of this cardioprotection by antagonism of either β1-adrenergic or δ-opioid receptors (δ-OR) suggests autonomic and/or opioidergic adaptations.To test the hypothesis that IHT shifts cardiac autonomic balance toward greater cholinergic and opioidergic influence.Mongrel dogs completed 20d IHT, non-hypoxic sham training, or IHT with the δ-OR antagonist naltrindole (200μg/kgsc). The vagolytic effect of the δ-OR agonist met-enkephalin-arg-phe delivered by sinoatrial microdialysis was evaluated following IHT. Sinoatrial, atrial and left ventricular biopsies were analyzed for changes in δ-OR, the neurotrophic monosialoganglioside, GM-1, and cholinergic and adrenergic markers.IHT enhanced vagal bradycardia vs. sham dogs (P0.05), and blunted the δ2-OR mediated vagolytic effect of met-enkephalin-arg-phe. The GM-1 labeled fibers overlapped strongly with cholinergic markers, and IHT increased the intensity of both signals (P0.05). IHT increased low and high intensity vesicular acetylcholine transporter labeling of sinoatrial nodal fibers (P0.05) suggesting an increase in parasympathetic arborization. IHT reduced select δ-OR labeled fibers in both the atria and sinoatrial node (P0.05) consistent with moderation of the vagolytic δ2-OR signaling described above. Furthermore, blockade of δ-OR signaling with naltrindole during IHT increased the protein content of δ-OR (atria and ventricle) and vesicular acetylcholine transporter (atria) vs. sham and untreated IHT groups. IHT also reduced the sympathetic marker, tyrosine hydroxylase in ventricle (P0.05).IHT shifts cardiac autonomic balance in favor of parasympathetic control via adaptations in opioidergic, ganglioside, and adrenergic systems. |
| Databáze: | OpenAIRE |
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