Changes Of TNFα And IL-6 In Serum And Spleens Of Neonatal Rats With Hypoxic-ischemic Brain Damage And The Effect Of Exogenous Melatonin On Them

Objective To study the change of tumor necrosis factorαand interleukin 6 in peripheral immune system of neonatal rats after hypoxic-ischemic brain damage and the effect of exogenous melatonin on them.Methods Postnatal 7-day-old Sprague-Dawley rats were randomly divided into five groups: sham operation group, model group (HIBD group), melatonin treated group. The serum and spleens were obtained in different times after HIBD, Radioimmunoassay (RIA) was used to observe the level of tumor necrosis factorαand interleukin 6 in serum, the mRNA of tumor necrosis factorα, interleukin 6 and melatonin receptor1 expressed in spleens was semi-quantitated by reverse transcriptase polymerase chain reaction(RT-PCR).Results In HIBD group,the tumor necrosis factorαin serum has raised at 2 hours after HIBD, peaked at 12 hours, and then decreased rapidly at 24 hours, RT-PCR showes that mRNA of TNF-αexpressed in spleen got to the peak at 8 hours and began to decline at 12 hours.The change tendency of TNF-αexpressed in serum and spleen in melatonin treated group were just similar to that of HIBD group. But there was a remarkable lower quantity in melatonin treated group compared to HIBD group at 2h,4h,8h,12h and 24h (p<0.01). The interleukin 6 in HIBD group in serum have no significant change at 8 hours,then to increase gradually at 12 hours.,and the expression of IL-6 mRNA detected in spleen began to increase at 8 hours and continued to rise at the later 16 hours. In melatonin treated group, IL-6 protein in serum and mRNA in spleen both rose at 2 hours,and to last until 24 hours ,and the quantity of IL-6 in melatonin treated group had always larger than HIBD group within 24 hours (p<0.01). Melatonin receptor 1 expressed in melatonin treated group had decreased dramaticly at 2 hours, lowest at 4 hours,then...