LONG-TERM EXPERIMENTALLY-INDUCED DIABETES AND CATECHOLAMINE METABOLISM IN RAT-BRAIN REGIONS

Tissue concentrations of dopamine (DA), their major metabolite 3,4-dih ydroxyphenilacetic acid (DOPAC) and noradrenaline (NA) were measured b y HPLC with electrochemical detection in brain areas (corpus striatum, cortex, hippocampus, hypothalamus, medulla pens, midbrain and amygdal a) and cerebellum of diabetic rats (streptozotocin-induced). Diabetic rats showed a statistically significant reduction of striatal DA and D OPAC levels and an increment of cerebellum and cortex DA content. Nora drenaline levels also increased in cerebellum and striatum. No changes were found in other brain regions. Only striatal NA and DA levels ret urned to control values after insulin replacement therapy. Data indica tes that DA metabolism in regions with high and low DA contents are di fferentially affected in diabetes since different neuronal processes a re altered in each dopamine brain area.