Clinical Implication of the Changes of cAMP, TXA_2 and PGI_2 in CSF of Asphyxiated Newborns

摘要

To evaluate the changes of 3', 5'-cyclic adenosine monophosphate (cAMP), thrombox-ane A_2(TXA_2) and prostacyclin (PGI_2) in cerebrospinal fluid (CSF) in the asphyxiated newborn and explore their roles in hypoxic-ischamic brain damage (HIBD). Thirty-six full term newborns were divided into 3 groups, including 12 with moderate-severe hypoxic-ischaemic encephalopathy (HIE). 13 with mild HIE, 11 without HIE (control group). The levels of cAMP, TXB_2(TXA_2 metabolite) and 6-keto-PGF_(1a)(PGI_2 metabolite) in CSF and plasma were measured 36-72 h after birth by RIA, and the concentrations were expressed as nM/L (cAMP), ng/L(TXB_2 and 6-keto-PGF_(1a)). The infants were followed-up at 6 and 12 month of age and Mental Development Index (MDI) and Psychomotor Development Index (PDD were measured using Bayley Scales of Infant Development (BSID). The CSF cAMP level in moderate-severe HIE group was 8. 60 +- 2. 40, significantly lower than that of the mild HIE group (14. 83 +- 2. 84) and the control group (24. 43 +- 2. 39)(for both P<0. 01). The levels of TXB_2 and 6-keto-PGF_(1a) in CFS in the moderate-severe HIE group (206. 06 +- 29. 74, 168. 47 +-23. 02, respectively) were significantly higher than in the mild HIE group (83. 37 +- 28. 57, 131. 42 +-16. 57, respectively, P<0. 01) and the control group (41. 77 +- 21. 58, 86. 23 +- 13. 05, respectively, P<0. 01). The level changes of cAMP, TXB_2 and 6-keto-PGF_(1a) in plasma in all groups were similar to those in CSF, but no significant difference was found between mild HIE group and the control group (P>0. 05). The follow-up results showed that MDI and PDI of the moderate-severe HIE group were the lowest (84. 79 +- 13. 34, 83. 50 +- 13. 28, respectively), followed by mild HIE group (102. 19 +- 7. 02, 99. 94 +- 9. 08, respectively), with the control group being the highest (116. 63 +-12.08, 116. 69 +- 10. 87, respectively). Univariate analysis showed some significant difference (the moderate-severe HIE group vs. the mild HIE group or the control group, P<0. 01; the mild HIE group vs. the control group P<0. 05). The results suggested that the concentration of cAMP, TXA_2 and T/K ratio in CSF after neonatal asphyxia might be sensitive markers in evaluating the severity of brain damage in early stage and predicting the future outcome.