title: Diazepam enhances intrasynaptosomal free calcium concentrations.
abstract: Synaptosomes prepared from brains of rats were incubated in different concentrations of diazepam under conditions designed to reduce the action of a reversed Na+/Ca2+ exchanger. In synaptosomes depolarized in the presence of added Ca2+, doses of diazepam ranging from 0.1 to 100 microM were found to significantly enhance Ca2+ levels measured with the fluorescent dye fura-2, compared to control incubations without drug. Furthermore, doses of diazepam as low as 1 microM significantly increased the concentration of Ca2+ in non-depolarized synaptosomes without added Ca2+ in the medium. The effects of depolarization and diazepam treatment were synergistic in increasing the levels of intrasynaptosomal Ca2+.
authors.affiliation: Department of Biology, Rutgers University, Camden, N.J. 08102.
authors.forename: J V
authors.initials: JV
authors.lastname: Martin
authors.forename: D R
authors.initials: DR
authors.lastname: Keir
authors.forename: H Y
authors.initials: HY
authors.lastname: Lee
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001921:Brain / Q000378:metabolism*; D002352:Carrier Proteins / Q000378:metabolism; D003975:Diazepam / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D016257:Fura-2; D007700:Kinetics; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D019831:Sodium-Calcium Exchanger; D013050:Spectrometry, Fluorescence; D013574:Synaptosomes / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology
chemical_list: D002352:Carrier Proteins; D019831:Sodium-Calcium Exchanger; D003975:Diazepam; D016257:Fura-2