Modulation of [³H]-D-Aspartate release and uptake in synaptosomes from ischemic retina.

(A) Ischemia reduced [³H]-D-Asp uptake in highly pure nerve ending. [³H]-D-Asp uptake into synaptosomes was measured in animals subjected to retinal ischemia for 50 min in the right eye and reperfused for 150 min (dashed line). The contralateral eye (solid line) was used as control. Data are expressed as mean ± S.E.M. (n = 3 or 4 animals per group). (B) [³H]-D-Asp release in retinal synaptosomes. Animals were subjected to retinal ischemia for 50 min in the right eye and reperfusion was allowed for 150 min. Release was measured in the ischemic (white histograms), contralateral (grey) and naïve retinas (black). All results are expressed as percentage of the corresponding KCl-evoked release (15 mM). Omission of Ca²⁺ produces a reduction of [³H]-D-Asp release of about 40% in all groups, while DL-TBOA reduces by about 60% the release in naïve and contralateral samples, but not in the ischemic retina. *p<0.05 vs control.