Glutamate and proline uptake by cerebral cortex synaptosomes during postnatal development

CHELUJA MG; SCOLARI MJ; BLAKE MG; BOCCIA MM; ACOSTA GB

San Luis, Argentina

Congreso; XXXV Reunión Científica Anual de la Asociación Argentina de Farmacología Experimental (SAFE); 2003

Asociación Argentina de Farmacología Experimental (SAFE)

During development, a number of reports demostrate the developmental change of the neuronal responses to excitatory and inhibitory transmitters. Here, we examined the influence of synaptic activity on Glutamate (Glu) and Proline (Pro) transporters responses in postnatal development. Both L-Pro and L-Glu are excitatory amino acids in the mammalian central nervous system. The fact that both amino acids are metabolically interconvertible in the brain, gives rise to an idea that the action of L-Pro could be partly mediated by processes associated with neurotransmission by L-Glu. Neonatal rat brain synaptosomes were freshly prepared for determination of incorporation of radiolabeled amino acids in Krebs Ringer buffer at 2°C and 30°C for different periods up to 30 min. The accumulation of [3H]-Pro and [3H]-Glu was almost abolished following replacement of NaCl by KCl in the incubation medium and reduction of incubation temperature from 30°C to 2°C, respectively. Neonatal rat brain synaptosomes could take up both radiolabeled amino acids in a fashion dependent on sodium ions and temperature. The data cited above suggest that temperaturedependent uptake may be at least in part involved in mechanisms associated with neuronal activities of both L-Pro and L-Glu during postnatal development.°C and 30°C for different periods up to 30 min. The accumulation of [3H]-Pro and [3H]-Glu was almost abolished following replacement of NaCl by KCl in the incubation medium and reduction of incubation temperature from 30°C to 2°C, respectively. Neonatal rat brain synaptosomes could take up both radiolabeled amino acids in a fashion dependent on sodium ions and temperature. The data cited above suggest that temperaturedependent uptake may be at least in part involved in mechanisms associated with neuronal activities of both L-Pro and L-Glu during postnatal development.