[3H]GABA and [3H]L-Serine uptake by brain syanptosomes during postnatal development and adulthood

COELHO TM; BLAKE MG; BOCCIA MM; ACOSTA GB

Tandil, Argentina

Congreso; XXXIV Reunión Científica Anual de la Asociación Argentina de Farmacología Experimental (SAFE); 2002

Asociación Argentina de Farmacología Experimental (SAFE)

GABA is the major inhibitory neurotransmitter in brain and participates in the central nervous system development. L-Serine does not seem to act as a neurotransmitter but apart from being a component of proteins and membrane phospholipids, has been proved to be an important neurotrophic factor. GABA uptake is the mechanism of ending the synaptic transmission and L-Serine uptake allows the entry of the amino acid into the neuron. In this work, we studied these two amino acids transport activity in synaptosomes obtained from neonate brains of 5, 7, 13 and 21 days of age, and from adult brains. The preparations were incubated with 10 nM of [3H]L-Serine or [3H]GABA in either the presence or absence of sodium or potassium chloride, at 2°C and 30°C, for different periods up to 30 min. At all ages [3H]GABA uptake showed a higher activity in the presence of Na+ and at 30°C. [3H]L-Serine uptake in neonates showed no preference for any ion or temperature condition. However, in adults, [3H]L-Serine transport activity was higher in the presence of Na+ and at 30°C. In these conditions and when incubated for 5 min, [3H]GABA and [3H]L-Serine uptake increased with age reaching values statistically higher in adults. We conclude that the way in which [3H]L-Serine and [3H]GABA are incorporated into synaptosomes by their specific transporters varies according to the temperature, cation and the age of the rats.