title: Action of protein kinase A activators on the caudal neuromuscular junction of toad tadpoles, recorded on synaptic spots.
abstract: Miniature end-plate currents (MEPCS), from synaptic spots on the caudal muscles of Bufo marinus tadpoles, were analyzed in both pre- and postsynaptic domains, when protein kinase A (PKA) activity modificators were used. Sp-cAMPS diasteromer induced an increase in MEPC frequency, which was completely reversed by Rp-cAMPS. However, changes in the decay time of MEPCS were not detected. Dibutyryl-cAMP produced a similar presynaptic action, but its postsynaptic action was similar to butyrate. Presynaptic effect of forskolin (FSK), if any, is masked by the increase of MEPC frequency produced by dimethylsulfoxide (DMSO), the solvent used.
authors.affiliation: Instituto de Biología Experimental, Facultad de Ciencias, Universidad Central de Venezuela, Caracas, Venezuela.
authors.forename: M
authors.initials: M
authors.lastname: Quiñonez
authors.forename: P J
authors.initials: PJ
authors.lastname: Romero
authors.forename: L
authors.initials: L
authors.lastname: Rojas
mesh_terms: D000287:Administration, Topical; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology; D003994:Bucladesine / Q000494:pharmacology; D002024:Bufo marinus / Q000254:growth & development*; D005576:Colforsin / Q000494:pharmacology; D017868:Cyclic AMP-Dependent Protein Kinases / Q000187:drug effects / Q000378:metabolism*; D004121:Dimethyl Sulfoxide / Q000494:pharmacology; D008564:Membrane Potentials / Q000187:drug effects; D009469:Neuromuscular Junction / Q000187:drug effects / Q000201:enzymology*; D018408:Patch-Clamp Techniques; D017729:Presynaptic Terminals / Q000187:drug effects / Q000502:physiology; D013569:Synapses / Q000187:drug effects / Q000201:enzymology*
chemical_list: D000893:Anti-Inflammatory Agents; D005576:Colforsin; D003994:Bucladesine; D017868:Cyclic AMP-Dependent Protein Kinases; D004121:Dimethyl Sulfoxide