Alpha 2-adrenergic regulation of galanin and norepinephrine release from canine pancreas
| Autor: | R. C. Veith, Thomas O. Mundinger, Gerald J. Taborsky, B. E. Dunning, A. J. W. Scheurink |
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| Rok vydání: | 1992 |
| Předmět: |
endocrine system
medicine.medical_specialty Sympathetic nervous system Physiology Neuropeptide Galanin Norepinephrine Dogs Physiology (medical) Internal medicine medicine Animals Pancreas Adrenergic alpha-Antagonists Chemistry digestive oral and skin physiology Neuropeptides Receptors Adrenergic alpha Yohimbine medicine.anatomical_structure Endocrinology nervous system Catecholamine Alpha-2 adrenergic receptor Peptides Adrenergic alpha-Agonists hormones hormone substitutes and hormone antagonists medicine.drug |
| Zdroj: | The American journal of physiology. 262(5 Pt 2) |
| ISSN: | 0002-9513 |
| Popis: | We found previously that electrical stimulation of the mixed autonomic pancreatic nerves (MPNS) is anesthesized dogs elicits marked and rapid increases of pancreatic output of both norepinephrine (NE) and galanin, and on that basis hypothesized a role for galanin as a sympathetic cotransmitter in the endocrine pancreas. In the present study, direct evidence was sought for the co-release of galanin and NE from canine pancreas by determining whether pancreatic galanin output is subject to modulation by presynaptic alpha 2-adrenergic mechanisms as has been established for NE. During MPNS (8 Hz, 1 ms, 10 mA, 10 min) in anesthesized dogs, both pancreatic NE and galanin outflow were increased with similar temporal patterns during consecutive stimulations. Blockade of presynaptic alpha 2-adrenoceptors with yohimbine increased and stimulation of presynaptic alpha 2-adrenoceptors with clonidine reduced NE and galanin outflow. Over all experiments, pancreatic spillover of galanin was highly correlated with that of NE. It is concluded that presynaptic alpha 2-adrenergic mechanisms modulate not only NE but also pancreatic galanin release, suggesting that galanin is co-released with NE from noradrenergic nerves in the endocrine pancreas. |
| Databáze: | OpenAIRE |
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