AMINO-ACID-TRANSPORT AFTER TRANSIENT GLOBAL-ISCHEMIA IN RATS - QUANTITATIVE AUTORADIOGRAPHIC STUDY USING 3-[I-125]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 subje cted to 30-min four-vessel occlusion according to the procedures devel oped by Pulsinelli prior to recirculation for 3, 6, 24, 48 and 72 h. W e used 3-[I-125]iodo-alpha-methyl-L-tyrosine as an autoradiographic tr acer for selective cerebral amino acid transport maker. Following 30-m in global ischemia, uptakes of 3-[I-125]iodo-alpha-methyl-L-tyrosine w ere significantly (P < 0.05) lower in substantia nigra, striatum and v entral tegmental area (6, 24, 48 and 72 h post-reperfusion), but signi ficantly (P < 0.05) higher in cortex and thalamus (3 and 6 h post-repe rfusion). The influence of transient global ischemia on cerebral amino acid transport manifested region-specific three different patterns; n amely, suppression, acceleration and no change in amino acid transport . The influence of transient ischemia on catecholamine-synthesizing br ain sites is most remarkable.