The Effect of Postnatal Dexamethasone Treatment on
Hypoxic-Ischemic Brain Injury in Neonatal Rats |
Chang Ro Park1, Kyung Pil Park1, Heng Mi Kim1, Yoon Kyung Sohn2 |
1Department of Pediatrics, College of Medicine, Kyungpook University, Taegu, Korea 2Department of Pathology, College of Medicine, Kyungpook University, Taegu, Korea |
신생쥐의 저산소성 허혈성 뇌손상에서 손상 후덱사메타손의 투여 효과 |
박창로1, 박경필1, 김행미1, 손윤경2 |
1경북대학교 의과대학 소아과학교실 2경북대학교 의과대학 병리학교실 |
Correspondence:
Heng Mi Kim, Email: hmkim@knu.ac.kr |
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Abstract |
Purpose : Dexamethasone is frequently administered to prevent or treat chronic lung disease in human neonates who are also prone to hypoxic-ischemic(HI) insults. Recently, meta-analysis of the follow-up studies reveals a significantly increased odd ratio for the occurrence of cerebral palsy or an abnormal neurologic outcome, and there is conflicting evidence regarding the impact of dexamethasone exposure on HI brain injury. This study was conducted to explore the effect of post-HI dexamethasone administration on neuronal injury in neonatal rats.
Methods : HI was produced in seven-day-old rats by right carotid artery ligation followed by two hours of 8% oxygen exposure. At the end of HI, the animals were injected intraperitoneally either with dexamethasone(0.5 mg/kg) or saline. Neuronal injury was assessed seven days after the HI by the area of infarction, TUNEL reactivity, Bcl-2 and Bax expression in brain.
Results : Post-insult dexamethasone administration resulted in reduction of weight gain and a higher mortality rate during seven days after HI. Dexamethasone treatment revealed no effect on the size of brain infarction induced by HI. Bax protein expression increased in dexamethasone treated brain but Bcl-2 protein expression and TUNEL reactivity revealed no significant differences between dexamethasone treated and non treated brain. Increased Bax protein expression suggest upregulation of the apoptosis by dexamethasone.
Conclusion : The result suggests the adverse role of Post-HI administration of dexamethasone in neonatal HI. |
Key Words:
Dexamethasone, Hypoxia-ischemia, neonatal rat, Apoptosis, Infarction size |
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