Biomaterial Database

Effect of flunarizine and calcium on serotonin uptake in human and rat blood platelets and rat synaptosomes. 1994

P N Jensen, and D F Smith, and J H Poulsen, and H J Møller, and R Rosenberg

Department of Biological Psychiatry, Psychiatric Hospital, Aarhus University Hospital, Risskov, Denmark.

Calcium and the calcium overload blocker flunarizine exert profound effects on mood. We therefore studied the effect of calcium and flunarizine on serotonin uptake in human and rat blood platelets and in rat synaptosomes. Calcium (1.3 mmol/L) had a weak inhibiting effect on serotonin uptake in blood platelets, whereas no effect was observed in synaptosomes. Flunarizine inhibited serotonin uptake in a concentration dependent manner with an IC50 value of 1 mumol/L in blood platelets and 5 mumol/L in synaptosomes. The inhibition did not depend on the presence of extracellular calcium indicating that the effect is not coupled to a blockade of cellular calcium influx. In human blood platelets, the inhibition was of the noncompetitive type. These results indicate that flunarizine interacts directly with the 5-HT uptake site. The relatively high concentration of flunarizine required to inhibit 5-HT uptake may question the clinical importance of this effect.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D011985	Receptors, Serotonin	Cell-surface proteins that bind SEROTONIN and trigger intracellular changes which influence the behavior of cells. Several types of serotonin receptors have been recognized which differ in their pharmacology, molecular biology, and mode of action.	5-HT Receptor,5-HT Receptors,5-Hydroxytryptamine Receptor,5-Hydroxytryptamine Receptors,Receptors, Tryptamine,Serotonin Receptor,Serotonin Receptors,Tryptamine Receptor,Tryptamine Receptors,Receptors, 5-HT,Receptors, 5-Hydroxytryptamine,5 HT Receptor,5 HT Receptors,5 Hydroxytryptamine Receptor,5 Hydroxytryptamine Receptors,Receptor, 5-HT,Receptor, 5-Hydroxytryptamine,Receptor, Serotonin,Receptor, Tryptamine,Receptors, 5 HT,Receptors, 5 Hydroxytryptamine
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
D002118	Calcium	A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.	Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D004305	Dose-Response Relationship, Drug	The relationship between the dose of an administered drug and the response of the organism to the drug.	Dose Response Relationship, Drug,Dose-Response Relationships, Drug,Drug Dose-Response Relationship,Drug Dose-Response Relationships,Relationship, Drug Dose-Response,Relationships, Drug Dose-Response
D005444	Flunarizine	Flunarizine is a selective calcium entry blocker with calmodulin binding properties and histamine H1 blocking activity. It is effective in the prophylaxis of migraine, occlusive peripheral vascular disease, vertigo of central and peripheral origin, and as an adjuvant in the therapy of epilepsy.	Flunarizin,Flunarizine Dihydrochloride,Flunarizine Hydrochloride,R-14950,Sibelium,Dihydrochloride, Flunarizine,Hydrochloride, Flunarizine,R 14950,R14950
D005625	Frontal Lobe	The part of the cerebral hemisphere anterior to the central sulcus, and anterior and superior to the lateral sulcus.	Brodmann Area 8,Brodmann's Area 8,Frontal Cortex,Frontal Eye Fields,Lobus Frontalis,Supplementary Eye Field,Area 8, Brodmann,Area 8, Brodmann's,Brodmanns Area 8,Cortex, Frontal,Eye Field, Frontal,Eye Field, Supplementary,Eye Fields, Frontal,Frontal Cortices,Frontal Eye Field,Frontal Lobes,Lobe, Frontal,Supplementary Eye Fields
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
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
D012701	Serotonin	A biochemical messenger and regulator, synthesized from the essential amino acid L-TRYPTOPHAN. In humans it is found primarily in the central nervous system, gastrointestinal tract, and blood platelets. Serotonin mediates several important physiological functions including neurotransmission, gastrointestinal motility, hemostasis, and cardiovascular integrity. Multiple receptor families (RECEPTORS, SEROTONIN) explain the broad physiological actions and distribution of this biochemical mediator.	5-HT,5-Hydroxytryptamine,3-(2-Aminoethyl)-1H-indol-5-ol,Enteramine,Hippophaine,Hydroxytryptamine,5 Hydroxytryptamine