"On" and "off" responses of K+-induced synaptosomal proline release: involvement of the sodium pump.
The K+-induced release of the putative neurotransmitter proline in rat cerebral cortex synaptosomes was studied by measuring [5-3H]proline released upon exposure to high-K+ media. In contrast to previous experiments, K+ was not substituted for Na+, which was held constant. Under the resulting conditions of increased osmolarity, two peaks of proline release were obtained, one upon exposure to increased [K+], another upon restoring normal [K+]. The dependence of the latter peak on ionic composition of the medium, and its sensitivity to ouabain are discussed.
D000818:Animals; D007473:Ion Channels / Q000378:metabolism*; D008297:Male; D010042:Ouabain / Q000494:pharmacology; D011188:Potassium / Q000494:pharmacology*; D011392:Proline / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D012964:Sodium / Q000378:metabolism*; D013574:Synaptosomes / Q000187:drug effects / Q000378:metabolism*; D014793:Visual Cortex / Q000378:metabolism
D007473:Ion Channels; D010042:Ouabain; D011392:Proline; D012964:Sodium; D011188:Potassium