ACUTE EFFECTS OF PERINATAL HYPOXIC INSULT ON CONCENTRATIONS OF DOPAMINE, SEROTONIN, AND METABOLITES IN FETAL MONKEY BRAIN

Seven monkeys (Macaca mulatta) were laparotomized under general anesth esia (halothane, nitrous oxide, oxygen). Fetal hypoxia was induced in four monkeys by occlusion of the umbilical cord with a hydraulic occlu der for 5-6 min. Three sham-operated fetuses served as controls. After unclamping, the fetuses were allowed to reperfuse for 20-30 min. To m onitor hypoxia, the fetal electrocardiogram was recorded continuously. Hypoxic insult was associated with a decrease in fetal heart rate dur ing the occlusion. After reperfusion, fetuses were immediately sacrifi ced and neocortex regions dissected on ice, frozen on dry ice and stor ed at -70 degrees C. Dopamine, 3,4-dihydroxyphenylacetic acid, homovan illic acid, serotonin, and 5-hydroxyindoleacetic acid were assayed by high performance liquid chromatography with electrochemical detection (HPLC/EC) in hippocampus, caudate nucleus and cortical regions. In the hippocampus, there was a significant increase in 5-hydroxyindoleaceti c acid concentration. In prefrontal cortex, there was a trend toward a n increase in serotonin but no effects on dopamine and homovanillic ac id concentrations. Dopamine, serotonin and metabolites were not altere d in the caudate nucleus. These data demonstrate that fetal hypoxia fo llowed by reperfusion produced an increase in serotonin concentration measured within the hippocampus and selected cortical areas known to b e targets of hypoxic injury.