Biomaterial Database

Release of noradrenaline by labetalol in the rat anococcygeus muscle. 1978

S A Doggrell, and D M Paton

The effects of labetalol on the accumulation and spontaneous release of (--)-[3H]noradrenaline, and on contractile responses to exogenously applied (--)-noradrenaline were studied in the isolated anococcygeus muscle of the rat. 1. Labetalol (3 x 10(-7)--10(-4)M) inhibited the accumulation of (--)-[3H]noradrenaline. 2. Labetalol (10(-6)--10(-4)M) and guanethidine (6 x 10(-6) M) increased the spontaneous release of [3H] following incubation of the muscle with (--)-[3H]noradrenaline. Nortriptyline (10(-6) M) had no effect on the spontaneous release of [3H], antagonised the increased release of [3H] produced by 6 x 10(-6) M guanethidine but not that observed with 10(-5) M labetalol. Labetalol (5 x 10(-6) M) markedly increased the loss of tritiated deminated metabolites with little change in the loss of (--)-[3H]noradrenaline. 3. Labetalol (10(-7)--10(-5)M), alone or in the presence of 10(-6) M nortriptyline, had no effect on contractile responses to (--)-noradrenaline. 4. Following pretreatment with 6-hydroxydopamine (10(-3)M for 3 h) to deplete endogenous noradrenaline stores, labetalol (10(-7)--10(-5) M) inhibited responses to exogenously applied (--)-noradrenaline. 5. These results suggest that, in the rat anococcygeus muscle, labetalol is a noradrenaline releasing agent and an alpha-adrenoceptor antogonist.

UI	MeSH Term	Description	Entries
D007741	Labetalol	A salicylamide derivative that is a non-cardioselective blocker of BETA-ADRENERGIC RECEPTORS and ALPHA-1 ADRENERGIC RECEPTORS.	AH-5158,Albetol,Apo-Labetalol,Dilevalol,Labetalol Hydrochloride,Labetalol, (R,R)-Isomer,Labetolol,Normodyne,Presolol,R,R-Labetalol,SCH-19927,Trandate,AH 5158,AH5158,Apo Labetalol,ApoLabetalol,Hydrochloride, Labetalol,R,R Labetalol,SCH 19927,SCH19927
D008297	Male		Males
D009119	Muscle Contraction	A process leading to shortening and/or development of tension in muscle tissue. Muscle contraction occurs by a sliding filament mechanism whereby actin filaments slide inward among the myosin filaments.	Inotropism,Muscular Contraction,Contraction, Muscle,Contraction, Muscular,Contractions, Muscle,Contractions, Muscular,Inotropisms,Muscle Contractions,Muscular Contractions
D009132	Muscles	Contractile tissue that produces movement in animals.	Muscle Tissue,Muscle,Muscle Tissues,Tissue, Muscle,Tissues, Muscle
D009638	Norepinephrine	Precursor of epinephrine that is secreted by the ADRENAL MEDULLA and is a widespread central and autonomic neurotransmitter. Norepinephrine is the principal transmitter of most postganglionic sympathetic fibers, and of the diffuse projection system in the brain that arises from the LOCUS CERULEUS. It is also found in plants and is used pharmacologically as a sympathomimetic.	Levarterenol,Levonorepinephrine,Noradrenaline,Arterenol,Levonor,Levophed,Levophed Bitartrate,Noradrenaline Bitartrate,Noradrénaline tartrate renaudin,Norepinephrin d-Tartrate (1:1),Norepinephrine Bitartrate,Norepinephrine Hydrochloride,Norepinephrine Hydrochloride, (+)-Isomer,Norepinephrine Hydrochloride, (+,-)-Isomer,Norepinephrine d-Tartrate (1:1),Norepinephrine l-Tartrate (1:1),Norepinephrine l-Tartrate (1:1), (+,-)-Isomer,Norepinephrine l-Tartrate (1:1), Monohydrate,Norepinephrine l-Tartrate (1:1), Monohydrate, (+)-Isomer,Norepinephrine l-Tartrate (1:2),Norepinephrine l-Tartrate, (+)-Isomer,Norepinephrine, (+)-Isomer,Norepinephrine, (+,-)-Isomer
D009661	Nortriptyline	A metabolite of AMITRIPTYLINE that is also used as an antidepressive agent. Nortriptyline is used in major depression, dysthymia, and atypical depressions.	Desitriptyline,Desmethylamitriptylin,Allegron,Apo-Nortriptyline,Aventyl,Gen-Nortriptyline,Norfenazin,Nortrilen,Nortriptyline Hydrochloride,Novo-Nortriptyline,Nu-Nortriptyline,PMS-Nortriptyline,Pamelor,Paxtibi,ratio-Nortriptyline,Apo Nortriptyline,Gen Nortriptyline,Hydrochloride, Nortriptyline,Novo Nortriptyline,Nu Nortriptyline,PMS Nortriptyline,ratio Nortriptyline
D004983	Ethanolamines	AMINO ALCOHOLS containing the ETHANOLAMINE; (-NH2CH2CHOH) group and its derivatives.	Aminoethanols
D006892	Hydroxydopamines	Dopamines with a hydroxy group substituted in one or more positions.	Hydroxydopamine
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013997	Time Factors	Elements of limited time intervals, contributing to particular results or situations.	Time Series,Factor, Time,Time Factor