The dynamic changes of plasma neuropeptide Y and neurotensin and their role in regulating cerebral hemodynamics in neonatal hypoxic-ischemic encephalopathy
The dynamic changes of plasma neuropeptide Y and neurotensin and their role in regulating cerebral hemodynamics in neonatal hypoxic-ischemic encephalopathy
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DOI：
10.1055/s-2007-985047
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发表时间：
2007-08-01
影响因子：
2
通讯作者：
Huang, Xing-Hua
中科院分区：
文献类型：
--
作者：
Liu, Jing;Zhao, Juan;Huang, Xing-Hua
新生儿缺氧缺血性脑病(HIE)是新生儿脑病的常见病因，也是导致新生儿死亡和残疾的重要原因之一，尤其是中、重度脑病的新生儿。然而，HIE的发病机制仍不清楚。本研究旨在探讨HIE患者血浆神经肽Y(NPY)和神经降压素(NT)的动态变化及其对脑血流动力学的调节作用。采用放射免疫法测定40例足月新生儿缺氧缺血性脑病(HIE)患儿出生后第1、3、7天脐动脉和外周血中NPY、NT的含量，并与40例正常新生儿作对照。出生第一天，超声检查结束后立即采集血样。于出生后第1天用脉冲多普勒超声检测两组大鼠大脑中动脉的血流动力学参数，包括收缩期峰值血流速度、舒张期末期血流速度、时间平均血流速度、搏动指数和阻力指数。用线性回归分析RI与NPY、NT的关系。新生儿缺氧缺血性脑病患儿脐血神经肽Y水平(平均标准差)为615.5±130.7 ng/L，新生儿出生后第1天外周血神经肽Y水平为355.9±57.4 ng/L，明显高于正常新生儿血(分别为199.1±63.2 ng/L和214.4±58.0 ng/L，P<0.01)。HIE新生儿的NPY水平在出生后第三天下降到对照水平(p>；0.05)。HIE组新生儿出生后第1周脐血和外周血中NT水平明显高于正常新生儿组(P<0.01)。超声检测结果显示，与正常对照组比较，HIE患者脑血流速度明显减慢，RI明显升高(P<0.01)。直线回归分析显示RI与NPY水平呈正相关(r=0.614；P<0.01)，与NT水平呈负相关(r=-0.579；P<；0.01)。结果表明，HIE患者血浆NPY、NT水平显著升高，且与HIE病情严重程度密切相关，血流动力学参数RI与NPY、NT显著相关。因此，我们认为新生儿窒息后血浆NPY、NT水平的动态变化可能通过调节脑血流动力学改变而参与HIE的发病机制。
Hypoxic-ischemic encephalopathy (HIE) is a common cause of neonatal encephalopathy and is one of the most important causes of neonatal death and disabilities, especially those infants with moderate to severe encephalopathy. However, the pathogenesis of HIE still remains unclear. The purpose of this study was to explore the dynamic changes in plasma neuropeptide Y (NPY) and neurotensin (NT) as well as their role in regulating cerebral hemodynamics in HIE patients. The plasma levels of NPY and NT in the umbilical artery and peripheral blood on the first, third, and seventh days after birth in 40 term infants with HIE and 40 healthy controls were measured using radioimmunoassay. On the first day of life, the blood samples were collected immediately when ultrasound examinations were finished. The ultrasound transducer was placed on the temporal fontanelle to detect the hemodynamic parameters of the middle cerebral artery, including peak systolic flow velocity, end-diastolic flow velocity, time-average mean velocity, pulsatility index, and resistance index (RI) in both groups were measured by pulse Doppler ultrasound in the first day after birth. The relationship between RI and NPY or NT was analyzed by linear regression analysis. NPY levels in umbilical blood ([mean standard deviation] 615.5 +/- 130.7 ng/L) and first-day peripheral blood (355.9 +/- 57.4 ng/L) in neonates with HIE were significantly higher than those in normal newborns' blood (199.1 +/- 63.2 and 214.4 +/- 58.0 ng/L, respectively; p < 0.01). NPY levels in HIE neonates then declined to control levels on the third day after birth (p > 0.05). However, the levels of plasma NT in umbilical blood and peripheral blood were much higher in the HIE group than those in normal newborns during the first week (p < 0.01). The results of Doppler ultrasound examinations showed that cerebral blood flow velocity significantly decreased, whereas RI increased markedly in HIE patients compared with healthy controls (p < 0.01). Linear regression analysis revealed that the RI was positively correlated with NPY levels (r= 0.614; p < 0.01) and negatively correlated with NT levels (r=-0.579; p < 0.01). The results of this study showed that there was a significant increase in plasma NPY and NT levels in HIE patients and this was strongly related to the severity of HIE, and the hemodynamic parameter RI was significantly correlated with NPY and NT. Therefore, we believe that the dynamic changes in plasma NPY or NT levels participate in the mechanisms of HIE by regulating cerebral hemodynamic changes after neonatal asphyxia occurs.