Biomaterial Database

Cyclothiazide modulates AMPA receptor-mediated increases in intracellular free Ca2+ and Mg2+ in cultured neurons from rat brain. 1995

K R Hoyt, and S Rajdev, and C L Fattman, and I J Reynolds

Department of Pharmacology, University of Pittsburgh, PA 15216, USA.

We investigated the modulation of (+/-)-alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA)-induced increases in intracellular free Ca2+ ([Ca2+]i) and intracellular free Mg2+ ([Mg2+]i) by cyclothiazide and GYKI 52466 using microspectrofluorimetry in single cultured rat brain neurons. AMPA-induced changes in [Ca2+]i were increased by 0.3-100 microM cyclothiazide, with an EC50 value of 2.40 microM and a maximum potentiation of 428% of control values. [Ca2+]i responses to glutamate in the presence of N-methyl-D-aspartate (NMDA) receptor antagonists were also potentiated by 10 microM cyclothiazide. The response to NMDA was not affected, demonstrating specificity of cyclothiazide for non-NMDA receptors. Almost all neurons responded with an increase in [Ca2+]i to both kainate and AMPA in the absence of extracellular Na+, and these Na(+)-free responses were also potentiated by cyclothiazide. GYKI 52466 inhibited responses to AMPA with an IC50 value of 12.0 microM. Ten micromolar cyclothiazide significantly decreased the potency of GYKI 52466. However, the magnitude of this decrease in potency was not consistent with a competitive interaction between the two ligands. Cyclothiazide also potentiated AMPA- and glutamate-induced increases in [Mg2+]i. These results are consistent with the ability of cyclothiazide to decrease desensitization of non-NMDA glutamate receptors and may provide the basis for the increase in non-NMDA receptor-mediated excitotoxicity produced by cyclothiazide.

UI	MeSH Term	Description	Entries
D007608	Kainic Acid	(2S-(2 alpha,3 beta,4 beta))-2-Carboxy-4-(1-methylethenyl)-3-pyrrolidineacetic acid. Ascaricide obtained from the red alga Digenea simplex. It is a potent excitatory amino acid agonist at some types of excitatory amino acid receptors and has been used to discriminate among receptor types. Like many excitatory amino acid agonists it can cause neurotoxicity and has been used experimentally for that purpose.	Digenic Acid,Kainate,Acid, Digenic,Acid, Kainic
D008274	Magnesium	A metallic element that has the atomic symbol Mg, atomic number 12, and atomic weight 24.31. It is important for the activity of many enzymes, especially those involved in OXIDATIVE PHOSPHORYLATION.
D009474	Neurons	The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.	Nerve Cells,Cell, Nerve,Cells, Nerve,Nerve Cell,Neuron
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
D002478	Cells, Cultured	Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.	Cultured Cells,Cell, Cultured,Cultured Cell
D004357	Drug Synergism	The action of a drug in promoting or enhancing the effectiveness of another drug.	Drug Potentiation,Drug Augmentation,Augmentation, Drug,Augmentations, Drug,Drug Augmentations,Drug Potentiations,Drug Synergisms,Potentiation, Drug,Potentiations, Drug,Synergism, Drug,Synergisms, Drug
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
D001569	Benzodiazepines	A group of two-ring heterocyclic compounds consisting of a benzene ring fused to a diazepine ring.	Benzodiazepine,Benzodiazepine Compounds
D001581	Benzothiadiazines	Heterocyclic compounds of a ring with SULFUR and two NITROGEN atoms fused to a BENZENE ring. Members inhibit SODIUM-POTASSIUM-CHLORIDE SYMPORTERS and are used as DIURETICS.
D014151	Anti-Anxiety Agents	Agents that alleviate ANXIETY, tension, and ANXIETY DISORDERS, promote sedation, and have a calming effect without affecting clarity of consciousness or neurologic conditions. ADRENERGIC BETA-ANTAGONISTS are commonly used in the symptomatic treatment of anxiety but are not included here.	Anti-Anxiety Agent,Anti-Anxiety Drug,Anxiolytic,Anxiolytic Agent,Anxiolytic Agents,Tranquilizing Agents, Minor,Anti-Anxiety Drugs,Anti-Anxiety Effect,Anti-Anxiety Effects,Antianxiety Effect,Antianxiety Effects,Anxiolytic Effect,Anxiolytic Effects,Anxiolytics,Tranquillizing Agents, Minor,Agent, Anti-Anxiety,Agent, Anxiolytic,Agents, Anti-Anxiety,Agents, Anxiolytic,Agents, Minor Tranquilizing,Agents, Minor Tranquillizing,Anti Anxiety Agent,Anti Anxiety Agents,Anti Anxiety Drug,Anti Anxiety Drugs,Anti Anxiety Effect,Anti Anxiety Effects,Drug, Anti-Anxiety,Drugs, Anti-Anxiety,Effect, Anti-Anxiety,Effect, Antianxiety,Effect, Anxiolytic,Effects, Anti-Anxiety,Effects, Antianxiety,Effects, Anxiolytic,Minor Tranquilizing Agents,Minor Tranquillizing Agents