title: High-affinity neurotensin receptor is involved in phosphoinositide hydrolysis stimulation by carbachol in neonatal rat brain.
abstract: Ontogenetic studies indicate that inositol phosphate accumulation in rodent brain tissue by cholinergic muscarinic agonists as well as expression of high-affinity neurotensin receptor (NTS1) peak at 7 days after birth. Herein, potential participation of this receptor in such effect was investigated. Cerebral cortex prisms of 7-day-old rats were preloaded with [3H]myoinositol and later incubated during 60 or 20 min in the presence of muscarinic agonist carbachol plus neurotensin and SR 48692, a non-peptide NTS1 antagonist. In 60-min incubation experiments, inositol phosphate accumulation by 10(-3) M carbachol was roughly 320%, an effect which remained unaltered plus 10(-6) M to 10(-4) M neurotensin but partially decreased with equimolar SR 48692 concentration. In 20-min incubation experiments, inositol phosphate accumulation by 10(-3) M carbachol was circa 240%, a value which attained 320-360% plus 10(-7) M neurotensin; this effect was totally blocked by 10(-7) M SR 48692. It was concluded that in inositol phosphate accumulation by carbachol, besides the cholinergic muscarinic receptor, the NTS1 receptor is likewise involved; findings at 60 min are attributable to the effect of endogenous neurotensin whereas those at 20 min most likely involve both endogenous and exogenously added peptide.
authors.affiliation: Instituto de Biología Celular y Neurociencias Prof. E. De Robertis, Facultad de Medicina, Universidad de Buenos Aires, Paraguay 2155, (1121) Buenos Aires, Argentina.
authors.forename: S
authors.initials: S
authors.lastname: Pereyra-Alfonso
authors.forename: M G
authors.initials: MG
authors.lastname: López Ordieres
authors.forename: M
authors.initials: M
authors.lastname: del V Armanino
authors.forename: G Rodríguez
authors.initials: GR
authors.lastname: de Lores Arnaiz
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001921:Brain / Q000187:drug effects* / Q000378:metabolism; D002217:Carbachol / Q000494:pharmacology*; D018679:Cholinergic Agonists / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D005260:Female; D006868:Hydrolysis / Q000187:drug effects; D007295:Inositol Phosphates / Q000493:pharmacokinetics; D008297:Male; D009496:Neurotensin / Q000494:pharmacology; D010716:Phosphatidylinositols / Q000378:metabolism*; D011720:Pyrazoles / Q000494:pharmacology; D011804:Quinolines / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D018028:Receptors, Neurotensin / Q000037:antagonists & inhibitors / Q000502:physiology*; D013997:Time Factors; D014316:Tritium
chemical_list: D018679:Cholinergic Agonists; D007295:Inositol Phosphates; D010716:Phosphatidylinositols; D011720:Pyrazoles; D011804:Quinolines; D018028:Receptors, Neurotensin; D014316:Tritium; C079087:SR 48692; D009496:Neurotensin; D002217:Carbachol