Biomaterial Database

Effect of prazosin on norepinephrine concentration and turnover in rat brain and heart. 1978

R W Fuller, and H D Snoddy, and K W Perry

Prazosin hydrochloride injected i.p. into rats markedly increased MOPEG sulfate (3-methoxy-4-hydroxy-phenylethylene glycol sulfate) concentration in brain and the rate of MOPEG sulfate accumulation after probenecid. The increase in MOPEG sulfate was dose-related over a 5-40 mg/kg dose range. After a 20 mg/kg dose of prazosin, the increase in MOPEG sulfate was greater than after the same dose of phenoxybenzamine and persisted for up to 24 hr. The rate of metaraminol disappearance from rat brain after alpha-methyl-m-tyrosine injection and the decline in brain norepinephrine after inhibition of its synthesis by alpha-methyltyrosine injection were increased in rats pretreated with prazosin. These findings indicate that prazosin increased brain norepinephrine turnover, probably via compensation to central alpha adrenoceptor blockade. Prazosin increased sertonin and 5-hydroxy-indoleacetic acid concentration and slightly decreased 3,4-dihydroxy-phenylacetic acid in rat brain. Although prazosin had little effect on brain norepinephrine concentration, heart norepinephrine was depleted for up to 16 hr after a 20 mg/kg dose of prazosin, and the depletion at 4 hr was dose-related down to 2 mg/kg of prazosin. These biochemical changes may all result from prazosin's block of alpha adrenergic receptors.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D008680	Metaraminol	A sympathomimetic agent that acts predominantly at alpha-1 adrenergic receptors. It has been used primarily as a vasoconstrictor in the treatment of HYPOTENSION.	Isophenylephrine,Metaradrin,m-Hydroxynorephedrine,meta-Hydroxynorephedrine,Aramine,Araminol,Hydroxyphenylpropanolamine,Metaraminol Bitartrate,Metaraminol Bitartrate (1:1),Metaraminol Tartrate,m-Hydroxyphenylpropanolamine,Bitartrate, Metaraminol,Tartrate, Metaraminol,m Hydroxynorephedrine,m Hydroxyphenylpropanolamine,meta Hydroxynorephedrine
D008734	Methoxyhydroxyphenylglycol	Synthesized from endogenous epinephrine and norepinephrine in vivo. It is found in brain, blood, CSF, and urine, where its concentrations are used to measure catecholamine turnover.	Hydroxymethoxyphenylglycol,MHPG,MOPEG,Vanylglycol,4-Hydroxy-3-methoxyphenylethylene Glycol,4-Hydroxy-3-methoxyphenylethyleneglycol,4-Hydroxy-3-methoxyphenylglycol,Methoxyhydroxyphenylglycol, (+)-Isomer,Methoxyhydroxyphenylglycol, (+-)-Isomer,Methoxyhydroxyphenylglycol, (-)-Isomer,4 Hydroxy 3 methoxyphenylethylene Glycol,4 Hydroxy 3 methoxyphenylethyleneglycol,4 Hydroxy 3 methoxyphenylglycol
D009206	Myocardium	The muscle tissue of the HEART. It is composed of striated, involuntary muscle cells (MYOCYTES, CARDIAC) connected to form the contractile pump to generate blood flow.	Muscle, Cardiac,Muscle, Heart,Cardiac Muscle,Myocardia,Cardiac Muscles,Heart Muscle,Heart Muscles,Muscles, Cardiac,Muscles, Heart
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
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
D011224	Prazosin	A selective adrenergic alpha-1 antagonist used in the treatment of HEART FAILURE; HYPERTENSION; PHEOCHROMOCYTOMA; RAYNAUD DISEASE; PROSTATIC HYPERTROPHY; and URINARY RETENTION.	Furazosin,Minipress,Pratsiol,Prazosin HCL,Prazosin Hydrochloride,HCL, Prazosin,Hydrochloride, Prazosin
D011799	Quinazolines	A group of aromatic heterocyclic compounds that contain a bicyclic structure with two fused six-membered aromatic rings, a benzene ring and a pyrimidine ring.	Quinazoline
D001923	Brain Chemistry	Changes in the amounts of various chemicals (neurotransmitters, receptors, enzymes, and other metabolites) specific to the area of the central nervous system contained within the head. These are monitored over time, during sensory stimulation, or under different disease states.	Chemistry, Brain,Brain Chemistries,Chemistries, Brain
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