Membrane Biophysics and BiochemistryMembrane Biophysics and Biochemistry: Influence of plasma membrane depolarization on cAMP level in rat brain synaptosomesFedorovich, Sergei V.1,3; Chubanov, Vladimir S.2; Sholukh, Mikhael V.2; Konev, Sergei V.1Author Information 1Institute of Photobiology, National Academy of Sciences of Belarus, Akademicheskaya St. 27, Minsk 220072, Belarus 2Department of Biochemistry, Belarus State University, Minsk 220080, Belarus CACorresponding Author: Sergei V. Fedorovich ACKNOWLEDGEMENT: This work was supported by the Small Research Grant CAN-ISN from International Society of Neurochemistry (ISN). Received 3 March 1999; accepted 13 April 1999 NeuroReport: June 3rd, 1999 - Volume 10 - Issue 8 - p 1763-1765 Buy 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. © 1999 Lippincott Williams & Wilkins, Inc.