脑脊液中cAMP浓度与新生儿窒息后脑损伤关系的临床研究

Relationship Between the cAMP Level in Cerebrospinal Fluid and Hypoxic Brain Damage Following Asphyxia in Newborns

摘要:

目的：脑细胞能量衰竭被认为是新生儿缺氧缺血性脑病(HIE)的重要发病机制之一，但如何评价其与脑损伤的关系报道较少。本研究通过检测窒息新生儿脑脊液(CSF)中环一磷酸腺苷(cAMP)的浓度变化以探讨其与脑损伤的关系。方法：36例足月新生儿，中重度HIE 12例，轻度HIE 13例，无HIE(对照组)11例。于生后36～72 h内取CSF和血液，放免法测定cAMP浓度。出院患儿于半岁、1岁时随访，运用贝利婴幼儿发展量表测定其智力发展指数(MDI)及精神运动发展指数(PDI)。结果：中重度HIE组CSF中cAMP浓度［(8.60±2.47) nmol/L］低于轻度组［(14.83±2.84) nmol/L］和对照组［(24.43±2.39) nmol/L］］，差异有显著性意义(P<0.01)；轻度组的CSF cAMP浓度也低于对照组(P<0.01)；而血浆中cAMP浓度亦是中重度HIE组最低，对照组最高，但轻度HIE组与对照组间差异无统计学意义(P>0.05)。中重度HIE组MDI和PDI分别为 84.79±13.34 和 83.50±13.28，低于轻度HIE组(102.19±7.02，99.94±9.08)和对照组(116.63±12.08，116.69±10.87)，差异均有显著性(P<0.01)，轻度HIE的MDI和PDI也小于对照组(P<0.05)。CSF中cAMP浓度与MDI及PDI呈高度正相关(r分别为 0.68，0.75，P均<0.01)。结论：CSF中cAMP浓度与缺氧性脑损伤关系密切，可作为新生儿窒息后早期评估脑损伤和评价预后的敏感指标之一。

Abstract:

OBJECTIVE: Energy failure of cerebral cells was regarded as one of the main mechanisms that led to hypoxic-ischemic encephalopathy(HIE) in the asphyxiated newborn. Few reports have discussed how to assess the relationship between energy failure and brain damage. The aim of the study is to explore the relationship between 3' , 5' -cyclin adenosine monophosphate (cAMP) and hypoxic brain damage by measuring the cAMP level in cerebrospinal fluid (CSF) of the asphyxiated newborn. METHODS: Thirty six full-term newborns were divided into three groups; moderate-severe HIE group (n= 12) , mild HIE group (n= 13) and non-HIE group (control group, n= 11). The levels of cAMP in CSF and plasma were measured by RIA between 36 hs and 72 hs after birth. The discharged newboms were followed up when they were 6 and 12 months old for measuring the mental development index (MDI) and psychomotor development index (PDI) by the Bayley Scales of Infant Development (BSID). RESULTS: The CSF cAMP level in the moderate-severe HIE group was (8.60±2.41) nmol/L, significantly lower than that of the mild HIE group [(14.83±2.84) nmol/L] and the control group [(24.43±2.39) nmol/L] (both P <0.01). There was a significant difference in the CSF cAMP level between the mild HIE group and control group ( P <0.01). The cAMP level in plasma in the moderate-severe group was the lowest, and that in the control group was the highest, but no significant difference was found between the mild HIE group and the control group. The results which were followed up showed that MDI and FDI of the moderate- severe HIE group were the lowest (84.79 ±13.34, 83.50±13.28, respectively); those of the mild HIE group were the second lowest (102.19±7.02, 99.94±9.08, respectively) and those of the control group were the highest (116.63±12.08, 116.69110.87, respectively). There were significant differences among the three groups ( P <0.01). ThecAMP level in CSF was significantly positively correlated to PDI and MDI ( r = 0.68, r =0.75,respectively, both P <0.01). CONCLUSIONS: There is a significant correlation between the cAMP level in CSF and hypoxic-ischamic brain damage. So the cAMP level in CSF following neonatal asphyxia might be used as one of the sensitive markers in evaluating the severity of brain damage at an early stage and predicting the future outcome.