title: Effects of benzodiazepines on potassium-induced increase in free cytosolic calcium concentration in astrocytes: interactions with nifedipine and the peripheral-type benzodiazepine antagonist PK 11195.
abstract: The benzodiazepines diazepam and midazolam at submicromolar concentrations potentiated the increase in free cytosolic calcium concentration in astrocytes in primary cultures evoked by an elevation of the extracellular potassium concentration ([K+]0), but they had little stimulatory effect at normal [K+]0 and none at maximally elevated [K+]0. Nifedipine, an inhibitor of the L-channel, counteracted both the effect of the elevated [K+]0 as such and the benzodiazepine modulation. PK 11195, an antagonist of the peripheral-type benzodiazepine receptor, counteracted the effect of the benzodiazepines, but had no effect on the increase in free cytosolic calcium evoked by the elevated [K+]0.
authors.affiliation: Department of Pharmacology, University of Saskatchewan, Saskatoon, Canada.
authors.forename: Z
authors.initials: Z
authors.lastname: Zhao
authors.forename: L
authors.initials: L
authors.lastname: Hertz
authors.forename: W E
authors.initials: WE
authors.lastname: Code
mesh_terms: D000818:Animals; D014151:Anti-Anxiety Agents / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D001253:Astrocytes / Q000187:drug effects* / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D003600:Cytosol / Q000187:drug effects / Q000378:metabolism; D003975:Diazepam / Q000037:antagonists & inhibitors / Q000494:pharmacology; D004347:Drug Interactions; D007546:Isoquinolines / Q000494:pharmacology*; D008564:Membrane Potentials / Q000187:drug effects; D051379:Mice; D008815:Mice, Inbred Strains; D008874:Midazolam / Q000037:antagonists & inhibitors / Q000494:pharmacology; D009543:Nifedipine / Q000494:pharmacology*; D011188:Potassium / Q000494:pharmacology*
chemical_list: D014151:Anti-Anxiety Agents; D002121:Calcium Channel Blockers; D007546:Isoquinolines; D009543:Nifedipine; D003975:Diazepam; D008874:Midazolam; D011188:Potassium; D002118:Calcium; C037850:PK 11195