[Effect of the Ca ionophore A-23187 on the plasmatic and mitochondrial potentials of the brain synaptosomes in rats: fluorescence measurements].

The applicability of the potential-sensitive dye diS-C3-(5) for the study of A23187 + Ca2+ induced plasma membrane hyperpolarization was tested in rat brain synaptosomes. An appropriate dye synaptosome ratio was chosen for the fluorescence titration dye in Ca-free Krebs-Ringer solution. The fluorescence intensity of the probe was increased upon the addition of Ca2+ (1 microM) to the synaptosomes in the presence of A23187 (1 microM).

[Interaction of isolated brain synaptic vesicles with flat bilayer membranes in the rat].

The conductivity of planar bilayer membrane comprising asolectin and phosphatidylserine (concentration ratio 9:1) in a buffer solution increased sharply in the presence of synaptic vesicles (SV) isolated from the rat brain and added to one side of the membrane only. The bilayer remained stable upon modification, and the conductivity increment was dependent on SV concentration in the range from 4 to 16 mu of the total protein per ml. If I mM CaCl2 was present in the buffer solution, the conductivity increased by 2 to 3 orders of magnitude upon the addition of SV at a final concentration of 3-4 mu protein per ml.