CATECHOLAMINERGIC DEVELOPMENT OF FETAL-RAT VENTRAL MESENCEPHALON - CHARACTERIZATION BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY WITH ELECTROCHEMICAL DETECTION AND IMMUNOHISTOCHEMISTRY

We determined dopamine (DA), noradrenaline (NA), and adrenaline (A), a s well as immunohistochemically stained tyrosine hydroxylase (TH) and DA in dissected rat ventral mesencephalon (VM) tissue from Embryonic D ay (ED) 14 to Postnatal Day (P) 17. Whole VM tissue DA, NA, and A cont ents increased with advancing age. VRI DA/protein increased from ED15 to ED16, whereas NA/protein increased from ED15 to ED16 and from ED20 to P4. VM DA/NA ratio increased from ED14 to ED15 and decreased from E D18 to P4. VM cell suspensions exhibited higher DA/NA ratios than whol e VM tissue. Washed cell suspensions had higher DA/NA than unwashed co unterparts. We conclude that data from both VM immunohistochemistry an d catecholamine assays relate to VRI development. VM DA is contained m ainly in cells, whereas VRI NA is located in fibers that channel at th e dorsal side of the VM. Determination of tissue catecholamine content s may be helpful for the biochemical characterization of tentatively i dentified VM grafts. (C) 1997 Academic Press.