Barkhuizen M, Van de Berg W D J, De Vente J, Blanco C E, Gavilanes A W D, Steinbusch H W M
Department Pediatrics, School for Mental Health and Neuroscience (MHeNs), Maastricht University, Maastricht, The Netherlands.
Department Psychiatry and Neuropsychology, School for Mental Health and Neuroscience (MHeNs), Maastricht University, Maastricht, The Netherlands.
Neurotox Res. 2017 Apr;31(3):400-409. doi: 10.1007/s12640-017-9700-6. Epub 2017 Jan 21.
Encephalopathy due to perinatal asphyxia (PA) is a major cause of neonatal morbidity and mortality in the period around birth. Preterm infants are especially at risk for cognitive, attention and motor impairments. Therapy for this subgroup is limited to supportive care, and new targets are thus urgently needed. Post-asphyxic excitotoxicity is partially mediated by excessive nitric oxide (NO) release. The aims of this study were to determine the timing and distribution of nitric oxide (NO) production after global PA in brain areas involved in motor regulation and coordination. This study focused on the rat striatum and cerebellum, as these areas also affect cognition or attention, in addition to their central role in motor control. NO/peroxynitrite levels were determined empirically with a fluorescent marker on postnatal days P5, P8 and P12. The distributions of neuronal NO synthase (nNOS), cyclic guanosine monophosphate (cGMP), astroglia and caspase-3 were determined with immunohistochemistry. Apoptosis was additionally assessed by measuring caspase-3-like activity from P2-P15. On P5 and P8, increased intensity of NO-associated fluorescence and cGMP immunoreactivity after PA was apparent in the striatum, but not in the cerebellum. No changes in nNOS immunoreactivity or astrocytes were observed. Modest changes in caspase-3-activity were observed between groups, but the overall time course of apoptosis over the first 11 days of life was similar between PA and controls. Altogether, these data suggest that PA increases NO/peroxynitrite levels during the first week after birth within the striatum, but not within the cerebellum, without marked astrogliosis. Therapeutic benefits of interventions that reduce endogenous NO production would likely be greater during this time frame.
围产期窒息（PA）所致脑病是出生前后新生儿发病和死亡的主要原因。早产儿尤其有认知、注意力和运动障碍的风险。该亚组的治疗仅限于支持性护理，因此迫切需要新的治疗靶点。窒息后兴奋性毒性部分由过量一氧化氮（NO）释放介导。本研究的目的是确定全脑PA后参与运动调节和协调的脑区中一氧化氮（NO）产生的时间和分布。本研究聚焦于大鼠纹状体和小脑，因为这些区域除了在运动控制中起核心作用外，还影响认知或注意力。在出生后第5、8和12天，用荧光标记物凭经验测定NO/过氧亚硝酸盐水平。用免疫组织化学法测定神经元型一氧化氮合酶（nNOS）、环磷酸鸟苷（cGMP）、星形胶质细胞和半胱天冬酶-3的分布。另外，通过测量出生后第2天至第15天的半胱天冬酶-3样活性来评估细胞凋亡。在出生后第5天和第8天，PA后纹状体中与NO相关的荧光强度和cGMP免疫反应性增加，但小脑中没有。未观察到nNOS免疫反应性或星形胶质细胞的变化。各组间观察到半胱天冬酶-3活性有适度变化，但PA组和对照组在出生后前11天的细胞凋亡总体时间进程相似。总之，这些数据表明，PA在出生后第一周内增加纹状体内的NO/过氧亚硝酸盐水平，但小脑中没有，且无明显星形胶质细胞增生。在此时间范围内，减少内源性NO产生的干预措施可能具有更大的治疗益处。
