Detection Of The Plasma Adrenomedullin(ADM) And Endothelin(ET) Levels In Neonatal Hypoxic-ischemic Encephalopathy(HIE) And Theirs Clinical Significance

Objective To study the dynamic changes of the plasma adrenomedullin(ADM) and endothelin(ET) levels in neonates with hypoxic-ischemic encephalopathy(HIE) in order to explore the relationship between the plasma ADM,ET levels and severity of hypoxic-ischemic brain damage and evaluate their clinical significance.Method The plasma ADM,ET levels were measured in 50 neonates with HIE and 20 healthy neonates by specific radoimmunoassay. The neonates with HIE were divided into mild HIE group(n=14),moderate HIE group(n=18) and sever HIE group(n=18) according to the clinical diagnosis and classification criteria. The peripheral blood samples of all neonates were obtained at the age of 0-3 days after birth . At the age of 14±4 days after birth, the neonates with HIE were drew peripheral blood again. Results The plasma ADM,ET levels increased significantly in neonates with HIE at the age of 0-3 days after birth(F=9.76,P<0.01), furthermore, had a tendency of increasing with the severity of HIE. The plasma ADM,ET levels in neonates with mild HIE were significantly higher than those of healthy neonates(46.47±6.47pg/ml and 34.64±6.29pg/ml；66.67±9.86 ng/l and 42.15±7.83 ng/l). The ADM,ET levels in moderate HIE and severe HIE were significantly higher than those of in mild HIE and moderate HIE(56.85±11.18pg/ml and 46.47±6.47pg/ml,72.79±13.20pg/ml and 56.85±11.18pg/ml；70.89±8.54ng/l and 66.67±9.86ng/l,82.37±9.24ng/l and 70.89±8.54ng/l). At the acute stage, the plasma ADM levels in moderate HIE and severe HIE were significantly lower than that of recovery stage(P<0.05,P<0.01),the ET levels in mild HIE and moderate HIE were significantly lower than that of recovery stage(P<0.01,P<0.01). But the ADM levels in mild HIE at acute stage were unsignificant than that of recovery stage(P>0.05), there are not obvious difference of the ET levels between acute stage and recovery stage in severe HIE (P>0.05). Besides, the plasma ADM levels was found to be positively correlated with the ET levels. Its correlation coefficient is 0.48 ( P<0.01). Conclusion These results indicated that the ADM and ET played a very important role in the pathophysiological process in neonates with HIE . High levels of ET as a harmful factor may increase hypoxic-ischemic brain damage(HIBD). High levels of ADM in the early stage of HIE may represent a defensive response, so it played an active role on maintaining the homeostasis of brain circulation and increasing the regional cerebral blood flow.