title: Influence of plasma membrane depolarization on cAMP level in rat brain synaptosomes.
abstract: We studied the influence of plasma membrane depolarization on cAMP content in presynaptic nerve endings (synaptosomes) isolated from brain hemispheres (HS) and cerebellum (CS). Depolarization by elevated [K+]o decreased basal cAMP level in both types of synaptosomes; reduced cAMP content in HS and increased cAMP in CS in the presence of IBMX; and lowered forskolin-stimulated cAMP accumulation in both the HS and the CS. Similar results were obtained when depolarization was induced by veratrine or when [Ca2+]i was elevated by treatment of the synaptosomes with the ionophore A23187. In Ca2+-free media, depolarization was not able to affect the synaptosomal cAMP levels. These data suggest that in brain synaptosomes intracellular cAMP pathway is modulated by alterations in [Ca2+]i.
authors.affiliation: Institute of Photobiology, National Academy of Sciences of Belarus, Minsk.
authors.forename: S V
authors.initials: SV
authors.lastname: Fedorovich
authors.forename: V S
authors.initials: VS
authors.lastname: Chubanov
authors.forename: M V
authors.initials: MV
authors.lastname: Sholukh
authors.forename: S V
authors.initials: SV
authors.lastname: Konev
mesh_terms: D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000378:metabolism* / Q000648:ultrastructure; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D002462:Cell Membrane / Q000502:physiology; D002531:Cerebellum / Q000201:enzymology / Q000502:physiology; D000242:Cyclic AMP / Q000378:metabolism*; D004594:Electrophysiology; D066298:In Vitro Techniques; D007476:Ionophores / Q000494:pharmacology; D008297:Male; D011188:Potassium / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013574:Synaptosomes / Q000378:metabolism*; D014702:Veratrine / Q000494:pharmacology
chemical_list: D007476:Ionophores; D000001:Calcimycin; D000242:Cyclic AMP; D000262:Adenylyl Cyclases; D014702:Veratrine; D011188:Potassium; D002118:Calcium; D015056:1-Methyl-3-isobutylxanthine