title: Neurotensin-induced release of endogenous noradrenaline from rat hypothalamic slices.
abstract: Effects of neurotensin on the release of endogenous noradrenaline (NA) from rat hypothalamic slices were investigated. NA was extracted by the aluminum adsorption method, and assayed electrochemically by high-performance liquid chromatography. Neurotensin (30-300 microM) enhanced the release of NA, in a dose dependent manner. Neurotensin 2 and 10 microM, doses without effect on the spontaneous release of NA, potentiated the potassium-induced release of this amine. Neurotensin 100 microM repetitively added to tbe medium at 40 min intervals induced a consistent and reproducible increase in the release of NA. This neurotensin-induced release of NA was completely abolished in calcium free medium containing EGTA 1 mM. The presence of tetrodotoxin 2 microM did not alter the effect of neurotensin 100 microM. These results of in vitro investigations suggest that neurotensin has a direct effect on NA nerve terminals in the hypothalamus and releases NA, in a Ca++-dependent manner.
mesh_terms: D000818:Animals; D002147:Calmodulin / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D007031:Hypothalamus / Q000187:drug effects* / Q000378:metabolism; D066298:In Vitro Techniques; D008297:Male; D009496:Neurotensin / Q000494:pharmacology*; D009638:Norepinephrine / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors
chemical_list: D002147:Calmodulin; D009496:Neurotensin; D009638:Norepinephrine