Biomaterial Database

Effect of clonidine on platelet alpha 2-adrenoreceptors and plasma norepinephrine of children with Tourette syndrome. 1985

F Silverstein, and C B Smith, and M V Johnston

Clonidine, an alpha 2-adrenoreceptor agonist, is useful for treating some patients with Tourette syndrome, and it has been suggested that their noradrenergic receptors are 'subsensitive'. The authors measured plasma norepinephrine and specific binding of 3H-clonidine and 3H-yohimbine, an alpha 2-adrenoreceptor antagonist, to receptors on platelet membranes from children with Tourette syndrome. Before clonidine treatment, plasma norepinephrine, the maximum number of binding sites and the dissociation constants for both ligands were the same as for the controls. After two weeks of treatment there was little clinical improvement, but the number of binding sites for 3H-yohimbine decreased and plasma norepinephrine also decreased in four of the five patients. Over the next six months all five patients continued to improve clinically, but both indices of noradrenergic activity returned towards baseline values. The data suggest that clonidine's action may be independent of its prominent effects on alpha 2-adrenergic receptors and norepinephrine release.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008297	Male		Males
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
D011869	Radioligand Assay	Quantitative determination of receptor (binding) proteins in body fluids or tissue using radioactively labeled binding reagents (e.g., antibodies, intracellular receptors, plasma binders).	Protein-Binding Radioassay,Radioreceptor Assay,Assay, Radioligand,Assay, Radioreceptor,Assays, Radioligand,Assays, Radioreceptor,Protein Binding Radioassay,Protein-Binding Radioassays,Radioassay, Protein-Binding,Radioassays, Protein-Binding,Radioligand Assays,Radioreceptor Assays
D011941	Receptors, Adrenergic	Cell-surface proteins that bind epinephrine and/or norepinephrine with high affinity and trigger intracellular changes. The two major classes of adrenergic receptors, alpha and beta, were originally discriminated based on their cellular actions but now are distinguished by their relative affinity for characteristic synthetic ligands. Adrenergic receptors may also be classified according to the subtypes of G-proteins with which they bind; this scheme does not respect the alpha-beta distinction.	Adrenergic Receptors,Adrenoceptor,Adrenoceptors,Norepinephrine Receptor,Receptors, Epinephrine,Receptors, Norepinephrine,Adrenergic Receptor,Epinephrine Receptors,Norepinephrine Receptors,Receptor, Adrenergic,Receptor, Norepinephrine
D001792	Blood Platelets	Non-nucleated disk-shaped cells formed in the megakaryocyte and found in the blood of all mammals. They are mainly involved in blood coagulation.	Platelets,Thrombocytes,Blood Platelet,Platelet,Platelet, Blood,Platelets, Blood,Thrombocyte
D002648	Child	A person 6 to 12 years of age. An individual 2 to 5 years old is CHILD, PRESCHOOL.	Children
D003000	Clonidine	An imidazoline sympatholytic agent that stimulates ALPHA-2 ADRENERGIC RECEPTORS and central IMIDAZOLINE RECEPTORS. It is commonly used in the management of HYPERTENSION.	Catapres,Catapresan,Catapressan,Chlophazolin,Clofelin,Clofenil,Clonidine Dihydrochloride,Clonidine Hydrochloride,Clonidine Monohydrobromide,Clonidine Monohydrochloride,Clopheline,Dixarit,Gemiton,Hemiton,Isoglaucon,Klofelin,Klofenil,M-5041T,ST-155,Dihydrochloride, Clonidine,Hydrochloride, Clonidine,M 5041T,M5041T,Monohydrobromide, Clonidine,Monohydrochloride, Clonidine,ST 155,ST155
D005879	Tourette Syndrome	A neuropsychological disorder related to alterations in DOPAMINE metabolism and neurotransmission involving frontal-subcortical neuronal circuits. Both multiple motor and one or more vocal tics need to be present with TICS occurring many times a day, nearly daily, over a period of more than one year. The onset is before age 18 and the disturbance is not due to direct physiological effects of a substance or another medical condition. The disturbance causes marked distress or significant impairment in social, occupational, or other important areas of functioning. (From DSM-IV, 1994; Neurol Clin 1997 May;15(2):357-79)	Gilles de la Tourette Disorder,Gilles de la Tourette's Disease,Tic Disorder, Combined Vocal and Multiple Motor,Chronic Motor and Vocal Tic Disorder,Combined Multiple Motor and Vocal Tic Disorder,Combined Vocal and Multiple Motor Tic Disorder,Gilles De La Tourette's Syndrome,Gilles de la Tourette Syndrome,Multiple Motor and Vocal Tic Disorder, Combined,Tourette Disease,Tourette Disorder,Tourette's Disease,Tourette's Disorder,Tourette's Syndrome,Syndrome, Tourette,Tourettes Disease,Tourettes Disorder,Tourettes Syndrome
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man