Effects of neonatal 6-hydroxydopa treatment on monamine content of rat brain and peripheral tissues

Treatment of rats from birth, with 6-hydroxydopa (6-OHDOPA) produced marked alterations in norepinephrine (NE) levels in the brain and spinal cord, but relatively slight changes in NE content of peripheral tissues, when rats were sacrificed at 5 weeks of age. In the neocortex, hippocampus and spinal cord 6-OHDOPA (60 mug/g i.p., 1 to 3 injections at 48 hr intervals from birth) resulted in a 20% to 85% reduction in NE. In the pons-medulla, midbrain and cerebellum, however, NE levels were elevated by 35% to 100%. Only slight alterations in NE were found in the hypothalamus, heart and spleen. Striatal levels of dopamine were unaltered by 6-OHDOPA at 5 weeks. Likewise, serotonin content of neocortex, cerebellum, pons-medulla, midbrain and hypothalamus was unchanged at 5 weeks, although slight elevations were seen in the neocortex and cerebellum at 2 weeks. The above effects indicate that neonatal 6-OHDOPA produces a relatively selective long term alteration of central stores of NE in the rat.