Possible Neuroprotective Role of Exogenous Growth Hormone on Hypoxic-Ischemic Brain Injury in Neonatal Rats |
Young Pyo Chang1, Mi Kyung Jung1, Youn Hee Jee1, Jae Ju Cho1, Soon Bum Lee1, Woo Sung Park1, Jong-Wan Kim2, Dong Hoon Shin3 |
1Department of Pediatrics, College of Medicine, Dankook University, Cheoan, Korea 2Department of Biological Sciences, Dankook University, Cheoan, Korea 3Department of Anatomy, College of Medicine, Seoul National University, Seoul, Korea |
신생 흰쥐의 저산소성-허혈성 뇌손상에 대한 성장 호르몬의 뇌보호 효과 |
장영표1, 정미경1, 지윤희1, 조재주1, 이순범1, 박우성1, 김종완2, 신동훈3 |
1단국대학교 의과대학 소아과학교실 2단국대학교 첨단과학대학 생물과학과 3서울대학교 의과대학 해부학교실 |
Correspondence:
Young Pyo Chang, Email: ychang@dankook.ac.kr |
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Abstract |
Purpose : This study was performed to evaluate the possible neuroprotective effect of exogenous growth hormone on hypoxic-ischemic brain injury in neonatal rats.
Methods : After ligation of the right common carotid artery, seven-day old Sprague-Dawley rats(n= 75) were exposed to 8% oxygen for two hours. In a growth hormone(GH)-treated group(n=25), each animal was subcutanously injected by GH(50 mg/kg, Grotrpin , Dong-Ah Pharmacy Co. KOREA) just before exposing to 8% oxygen, and then injected for the next two consecutive days by the same method. In a saline-treated group(n=25), the same amounts of saline were injected instead of GH. Other twenty five animals were sham-operated without hypoxia as a sham control group. The gross morphologic changes of extracted brains at three and seven days after injury were observed, and the ratios of wet and dry weight of each cerebral hemisphere ipsilateral and contralateral to hypoxic-ischemic injury were compared among three groups for evaluating the severity of brain edema. Also, the microscopic changes of cerebral cortex on coronal sections of paraffin-embedded brains were observed at three days after injury by light microscopy.
Results : The GH injection reduced the severities of gross changes at seven days after HI injury. The brain edemas of ipsilateral cerebral hemispheres to the site of ligation of the right common carotid artery were significantly decreased in GH-treated animals at three days after HI injury, compared to those in saline-treated animals(P<0.05). On light microscopic examination, neurons with pyknosis of nucleus were remarkably reduced on cerebral cortex at three days after hypoxic-ischemic injury by GH treatment.
Conclusion : Exogenous GH might have a some neuroprotective role in hypoxic-ischemic brain injury of newborn rats. |
Key Words:
Growth hormone, Hypoxic-ischemic injury, Apoptosis, Brain, Newborn |
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