Amino acid transport after transient global ischemia in rats: quantitative autoradiographic study using 3-[125I]iodo-alpha-methyl-L-tyrosine

We studied the influence of reperfusion on amino acid transport of the brain after transient global ischemia in rats. The animals were subjected to 30-min four-vessel occlusion according to the procedures developed by Pulsinelli prior to recirculation for 3, 6, 24, 48 and 72 h. We used 3-[125I]iodo-alpha-methyl-L-tyrosine as an autoradiographic tracer for selective cerebral amino acid transport maker. Following 30-min global ischemia, uptakes of 3-[125I]iodo-alpha-methyl-L-tyrosine were significantly (P < 0.05) lower in substantia nigra, striatum and ventral tegmental area (6, 24, 48 and 72 h post-reperfusion), but significantly (P < 0.05) higher in cortex and thalamus (3 and 6 h post-reperfusion). The influence of transient global ischemia on cerebral amino acid transport manifested region-specific three different patterns; namely, suppression, acceleration and no change in amino acid transport. The influence of transient ischemia on catecholamine-synthesizing brain sites is most remarkable.