title: Delayed neuronal migration of protein kinase Cgamma immunoreactive cells in hippocampal CA1 area after 48 h of moderate hypoxemia in the near term ovine fetus.
abstract: The brain is uniquely sensitive to disturbances in energy and oxygen supply, particularly during the early stage of life. Since hypoxemia can indirectly activate the intracellular messenger protein kinase C (PKC), we studied the PKCgamma-immunoreaction in the fetal hippocampal CA1 region of naive (n=4), instrumented control (n=7), and instrumented hypoxemic fetuses (n=14), at a mean gestational age of 127 days. Forty-eight hours of mild to moderate hypoxemia, were followed by a 48-h recovery period. Hypoxemia resulted in an increase in carotid blood flow (137% of control), and a shift towards a higher percentage of high-voltage electrocortical activity. After recovery, the fetal brain was fixated by perfusion of both carotid arteries, sectioned and immunostained for PKCgamma. The distribution of PKCgamma-immunoreactive cells was significantly changed after 48 h of hypoxemia in that the migration of cells (from the ventricular region towards the stratum pyramidale) was delayed (p<0.01) compared to naive and instrumented control animals. In contrast to the distribution, the relative total optical density of PKCgamma-ir cells and fibres in the CA1 hippocampal area was not significant different between the animal groups. We conclude that hypoxemia delayed migration of PKCgamma-ir cells, without neuronal degeneration.
mesh_terms: D000818:Animals; D005260:Female; D005312:Fetal Blood; D005333:Fetus; D005865:Gestational Age; D006624:Hippocampus / Q000196:embryology* / Q000201:enzymology / Q000503:physiopathology; D000860:Hypoxia / Q000196:embryology* / Q000201:enzymology; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000032:analysis*; D009474:Neurons / Q000201:enzymology / Q000502:physiology*; D010100:Oxygen / Q000097:blood; D010313:Partial Pressure; D011247:Pregnancy; D011493:Protein Kinase C / Q000032:analysis*; D017966:Pyramidal Cells / Q000201:enzymology / Q000502:physiology*; D012756:Sheep; D013997:Time Factors