Comparative study of neonatal rat models of hypoxia-ischemia induced white matter injury of brain / 中国小儿急救医学

ABSTRACT

Objective To investigate the difference among neonatal rat models of hypoxia-ischemia induced white matter injury of brain by three different methods and to provide theory basis on choosing the proper animal model for deep study on white matter injury of premature infants.Methods Three different hypoxia-ischemia methods were applied to induce brain white matter injury model of Wistar rats of postnatal 3rd day which were left carotid artery ligation followed by 6％ oxygen for 30 minutes and for 4 hours respectively,and bilateral carotid artery ligation followed by 8％ oxygen for 30 minutes.Compared brain pathological results of rats in different groups,changes in white matter of brain by glial fibrillary acidic protein (GFAP) and myelin basic protein (MBP) immunostaining,and changes in time of opening eyes and eyes appearance.Results Left carotid artery ligation followed by 6％ oxygen for 30 minutes resulted in sparse and vague periventricular white matter without necrotic lesions,and the degree of GFAP intensity [(5 021.63 ± 358.92) OD] increase and MBP intensity [(18 488.63 ± 1 822.62) OD] decrease were lowest (P ＜ 0.000 1),as well as the delay of opening time of the left eye.Left carotid artery ligation followed by 6％ oxygen for 4 hours resulted in necrotic lesions of periventricular white matter,with the degree of GFAP intensity [(6 069.13 ± 458.61) OD] and MBP intensity [(15 003.38 ± 1 559.11) OD],and also the delay of opening time of the left eye.Bilateral carotid artery ligation followed by 8％ oxygen for 30 minutes caused cystic necrosis of bilateral periventricular white matters,and the degree of GFAP intensity [(6 194.50 ±432.69) OD] increase and MBP intensity [(10 119.35 ± 735.16) OD] decrease of the left side were highest(P ＜ 0.000 1),as well as the delay of opening time and cataract in both eyes.Conclusion Left carotid artery ligation followed by 6％ oxygen for 30 minutes is more suitable for investigating mild brain white matter injury.Left carotid artery ligation followed by 6％ oxygen for 4 hours and bilateral carotid artery ligation followed by 8％ oxygen for 30 minutes are more proper for the investigation of severe periventricular leukemacia cases.