Neurotensin affects metabolism of opioid peptides, catecholamines and inositol phospholipids in bovine chromaffin cells |
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Authors: | M Bommer A Herz |
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Institution: | Department of Neuropharmacology, Max-Planck-Institut für Psychiatrie, Martinsried, Federal Republic of Germany. |
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Abstract: | Bovine adrenal medullary cells released significant amounts of opioid pentapeptides Met- and Leu-enkephalin and catecholamines, when stimulated by neurotensin (NT). Maximal release induced by this peptide was about 40-50% of that seen after nicotinic activation of cholinergic receptors. Dose-response curves for neurotensin-induced secretion revealed an EC50 of 1x10(-6)M, thereby being in the range of that for acetylcholine or nicotine. Secretory effects were dependent on extracellular Ca++ and impaired by the Ca++ channel blocker D 600. Moreover NT produced an increase in opioid peptide cell content after 48 and 72 hrs of incubation. Besides affecting opioid peptide metabolism, NT significantly produced accumulation of inositol- 1-phosphates (IP1), the significance of which remains to be clarified in the observed metabolic effects. |
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