Effect of Hypoxia-Ischemia on Striatal Monoamine Metabolism in
Neonatal Rat Brains |
Youn Hee Jee1, Hyung Gun Kim2, Woo Sung Park1, Young Pyo Chang1 |
1Department of Pediatrics, Collage of Medicine, Dankook University, Cheonan, Korea 2Department of Pharmacology, Collage of Medicine, Dankook University, Cheonan, Korea |
저산소-허혈 손상이 신생 흰쥐의 뇌 선조체(Striatum)Monoamine 대사에 미치는 영향 |
지윤희1, 김형건2, 박우성1, 장영표1 |
1단국대학교 의과대학 소아과학교실 2단국대학교 의과대학 약리학교실 |
Correspondence:
Young Pyo Chang, Email: ychang@dku.edu |
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Abstract |
Purpose : We intended to evaluate the effect of hypoxia-ischemia on extracellular striatal monoamine metabolism in neonatal rat brains by in vivo microdialysis.
Methods : The right common carotid arteries of five or six-day old rats were surgically ligated, and the probes for microdialysis were inserted into the right striatum with stereotaxic instrument. After stabilization for two hours, artificial cerebrospinal fluid was infused via the probe for microdialysis and samples were collected during hypoxia-ischemia and recovery periods at 20 minute intervals. The concentrations of DA(dopamine), DOPAC(3,4-di-hydroxyphenyl acetic acid), HVA(homovanillic acid), NE(norepinephrine), and 5-HIAA(5-hydroxy indole-acetic acid) were measured by HPLC(high performance liquid chromatography) and the changes were analysed.
Results : The striatal levels of dopamine metabolites such as DOPAC and HVA, were significantly decreased during hypoxia-ischemia, and increased to their basal level during reoxygenation(P<0.05). Dopamine mostly increased during hypoxia but statistically not significant(P>0.05). DOPAC showed the most remarkable decrease(23.0?.2%, P<0.05), during hypoxia-ischemia and increase to the basal levels during reoxygenation(120.8?4.9%, P<0.05), and HVA showed the same pattern of changes as those of DOPAC during hypoxia-ischemia(35.3?.6% of basal level, P<0.05) and reoxygenation (105.8?2.3%). However, the level of NE did not show significant changes during hypoxia-ischemia and reoxygenation. The levels of 5-HIAA decreased(74.9?.1%) and increased(118.1?.8%) during hypoxia-ischemia and reoxygenation, respectively(P<0.005).
Conclusion : Hypoxia-ischemia had a significant influence on the metabolism of striatal monoamine in neonatal rat brains. These findings suggest that monoamine, especially dopamine, and its metabolites could have a significant role in the pathogenesis of hypoxic-ischemic injury of neonatal rat brains. |
Key Words:
Hypoxia-Ischemia, Striatum, Monoamine, Newborn |
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