RESUMO
In nervous tissue, the calcium (Ca(2+)) release induces neurotransmitter exocytosis and synaptic plasticity in neurons and is essential for Ca(2+) waves and oscillations in astrocytes. In this work, we have investigated the effect of organocalchogens on calcium influx in synaptosomal preparations under basal and depolarizing conditions. Acute administration of ebselen caused a significant increase of 34% (p < 0.05) Ca(2+) influx, when under basal conditions but showed no effect on potassium stimulated calcium conditions by brain synaptosomes. Diphenyl ditelluride (PhTe)(2) increased (45)Ca(2+) influx by 40% (p < 0.05) under depolarizing conditions, while diphenyl diselenide (PhSe)(2) had no effect on the brain synaptosomes studied. In addition, we characterized an "in vitro" model with the purpose of studying Ca(2+) movements in slices. In this model, we examined the effect of diorganylchalcogenides using brain hippocampal slices, which showed the decrease of calcium influx with the three drugs studied. These findings showed that there are different effects of diorganylchalcogenides in the different models evaluated. It is possible that these differential effects result from the action of neural signal transduction pathways at different levels, possibly involving neurotransmitter release and channel targeting.
