Biomaterial Database

Release of endogenous noradrenaline from an isolated muscular artery. Release of endogenous noradrenaline from an isolated muscular artery. 1971

C Bell, and M Vogt

1. The release of noradrenaline by field stimulation of vasoconstrictor nerves has been studied in isolated preparations of the main uterine artery of the guinea-pig.2. In preparations from virgin animals stimulation with trains of 3000 square pulses at 5 and 25 pulses/sec resulted in mean overflows of 0.56 ng/g.pulse and 1.53 ng/g.pulse respectively.3. Inhibition of monoamine oxidase and catechol-O-methyltransferase had no consistent effect on overflow at either stimulation frequency.4. Desmethylimipramine (10(-5)M) caused, on the average, a 2.4-fold increase in overflow following stimulation at 5 pulses/sec while phenoxybenzamine (10(-5)M) caused a 3.8-fold increase. Neither of these drugs caused a significant alteration of the overflow during stimulation at 25 pulses/sec.5. Treatment of the tissues with desmethylimipramine plus normetanephrine (4.5 x 10(-4)M) caused no more increase in overflow than treatment with desmethylimipramine alone.6. It is concluded that enzymatic metabolism of noradrenaline at the synapse is of little functional importance in this tissue, and that the most important mechanism of transmitter inactivation is by nervous re-uptake. Although phenoxybenzamine was more effective than desmethylimipramine in increasing transmitter overflow, no evidence was obtained to support the view that this effectiveness was due partly to blockade of ;Uptake 2'.7. There was sometimes very low overflow of noradrenaline from arteries taken from animals in the last week of pregnancy. In these instances overflow following stimulation at 5 pulses/sec was not increased by phenoxybenzamine treatment of the tissue.8. Methylene blue and fluorescence microscopic techniques indicated that the terminal adrenergic axons in each artery possess approximately 8.74 x 10(5) varicosities. The mean tissue content of noradrenaline was found to be 9.6 mug/g or 29 ng/artery. These results have been correlated with known morphological and electrophysiological data to derive a peak post-junctional concentration of noradrenaline during transmission of about 4 x 10(-4)M.9. The fraction of total noradrenaline content of the artery released per pulse (under the influence of phenoxybenzamine) had a mean value of 2.2 x 10(-4).

UI	MeSH Term	Description	Entries
D007490	Iproniazid	An irreversible inhibitor of monoamine oxidase types A and B that is used as an antidepressive agent. It has also been used as an antitubercular agent, but its use is limited by its toxicity.	Iprazid
D007659	Ketones	Organic compounds containing a carbonyl group	Ketone
D008751	Methylene Blue	A compound consisting of dark green crystals or crystalline powder, having a bronze-like luster. Solutions in water or alcohol have a deep blue color. Methylene blue is used as a bacteriologic stain and as an indicator. It inhibits GUANYLATE CYCLASE, and has been used to treat cyanide poisoning and to lower levels of METHEMOGLOBIN.	Methylthionine Chloride,Swiss Blue,Basic Blue 9,Chromosmon,Methylene Blue N,Methylthioninium Chloride,Urolene Blue,Blue 9, Basic,Blue N, Methylene,Blue, Methylene,Blue, Swiss,Blue, Urolene
D008856	Microscopy, Fluorescence	Microscopy of specimens stained with fluorescent dye (usually fluorescein isothiocyanate) or of naturally fluorescent materials, which emit light when exposed to ultraviolet or blue light. Immunofluorescence microscopy utilizes antibodies that are labeled with fluorescent dye.	Fluorescence Microscopy,Immunofluorescence Microscopy,Microscopy, Immunofluorescence,Fluorescence Microscopies,Immunofluorescence Microscopies,Microscopies, Fluorescence,Microscopies, Immunofluorescence
D008996	Monoamine Oxidase Inhibitors	A chemically heterogeneous group of drugs that have in common the ability to block oxidative deamination of naturally occurring monoamines. (From Gilman, et al., Goodman and Gilman's The Pharmacological Basis of Therapeutics, 8th ed, p414)	MAO Inhibitor,MAO Inhibitors,Reversible Inhibitors of Monoamine Oxidase,Monoamine Oxidase Inhibitor,RIMA (Reversible Inhibitor of Monoamine Oxidase A),Reversible Inhibitor of Monoamine Oxidase,Inhibitor, MAO,Inhibitor, Monoamine Oxidase,Inhibitors, MAO,Inhibitors, Monoamine Oxidase
D009130	Muscle, Smooth	Unstriated and unstriped muscle, one of the muscles of the internal organs, blood vessels, hair follicles, etc. Contractile elements are elongated, usually spindle-shaped cells with centrally located nuclei. Smooth muscle fibers are bound together into sheets or bundles by reticular fibers and frequently elastic nets are also abundant. (From Stedman, 25th ed)	Muscle, Involuntary,Smooth Muscle,Involuntary Muscle,Involuntary Muscles,Muscles, Involuntary,Muscles, Smooth,Smooth Muscles
D009435	Synaptic Transmission	The communication from a NEURON to a target (neuron, muscle, or secretory cell) across a SYNAPSE. In chemical synaptic transmission, the presynaptic neuron releases a NEUROTRANSMITTER that diffuses across the synaptic cleft and binds to specific synaptic receptors, activating them. The activated receptors modulate specific ion channels and/or second-messenger systems in the postsynaptic cell. In electrical synaptic transmission, electrical signals are communicated as an ionic current flow across ELECTRICAL SYNAPSES.	Neural Transmission,Neurotransmission,Transmission, Neural,Transmission, Synaptic
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
D009647	Normetanephrine	A methylated metabolite of norepinephrine that is excreted in the urine and found in certain tissues. It is a marker for tumors.	3-Methoxynoradrenaline,Normetadrenaline,3 Methoxynoradrenaline
D010643	Phenoxybenzamine	An alpha-adrenergic antagonist with long duration of action. It has been used to treat hypertension and as a peripheral vasodilator.	Dibenylene,Dibenyline,Dibenziran,Dibenzylin,Dibenzyline,Dibenzyran,Phenoxybenzamine Hydrochloride,Hydrochloride, Phenoxybenzamine