Neurotensin affects metabolism of opioid peptides, catecholamines and inositol phospholipids in bovine chromaffin cells.
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.
Bommer
M
M
Department of Neuropharmacology, Max-Planck-Institut für Psychiatrie, Martinsried, Federal Republic of Germany.
Herz
A
A
D000313:Adrenal Medulla / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D004743:Enkephalin, Leucine / Q000378:metabolism; D004744:Enkephalin, Methionine / Q000378:metabolism; D004745:Enkephalins / Q000378:metabolism*; D007295:Inositol Phosphates / Q000378:metabolism*; D009496:Neurotensin / Q000494:pharmacology*; D009638:Norepinephrine / Q000378:metabolism*; D013403:Sugar Phosphates / Q000378:metabolism*
D004745:Enkephalins; D007295:Inositol Phosphates; D013403:Sugar Phosphates; C002647:inositol 1-phosphate; D009496:Neurotensin; D004744:Enkephalin, Methionine; D004743:Enkephalin, Leucine; D009638:Norepinephrine