原著

著者

Yasuhito HAYAKAWA, Naoki MASAOKA, Satoshi HAMANO,
Sachiko OHGAME, Hisaei SAKATA and Tatsuo YAMAMOTO
Department of Obstetrics and Gynecology, Nihon University School of Medicine

要旨

Objective: To evaluate the relationship of histological change and concentration of amino acids (gultamete,asparate, glycine and g -aminobutyric acid: GABA) in fetal brain by intermittent partial umbilical cord occlusion inchronically instrumented fetal lambs. Methods: The ischemia-reperfusion insult in the fetal brain was induced byumbilical cord occlusion for 1 of every 3 minutes for 2 hours. Fetal brains were extracted 3 days after the experimentalinsult and were used for pathologic evaluation. Simultaneously changes of amino acids concentration in thefetal brain, were analyzed by a brain microdialysis method during intermittent umbilical cord occlusion.

Results: [1] Mild decrease in fetal PaO2 of about 5 mmHg was found without changes in PCO2, pH duringintermittent umbilical cord occlusion. [2] In fetal brains extracted 3 days after the experimental insult, apoptoticcells were confirmed by TUNEL staining of the periventricular region, basal ganglia and hippocampus of the fetalbrains. [3] While the fetal brain tissues showed apparent increases in the insult induced excitatory amino acids suchas glutamates, there were no changes of asparates and glycine throughout experimental protocol. [4] There wassignificant decrease in GABA which is said to suppress cellular death, and resulting in an excitotoxic index where[glutamate ´ glycine/GABA] increased. Conclusions: Fetal brain damage caused by intermittent occlusion ofumbilical circulation may have a association with changes of amino acid in fetal brain tissue.

keyword

umbilical cord, brain damage, apoptosis, excitatory amino acids, g -aminobutyric acid