The Expression Of Cytoglobin On The Hypoxia-ischemic Brain Damage In The Neonatal Rats

Almost all neonatal hypoxic-ischemic encephalopathy(HIE) was caused by heavy asphyxia and hypoxia during the perinatal period .Recently,the brain injury after asphyxia and hypoxia was paid more attention.Cytoglobin(CYGB) is a newly discovered vertebrate heme protein that mainly expressed in the whole body and can bind oxygen reversibly,transport and store oxygen.It has been reported that CYGB act as a hypoxia-inducible neuron protecting factor to promote neuronal survival from hypoxia-ischemic insults.The discovery of CYGB offers the new ways for HIE.The expressing experiments of CYGB after the hypoxic-ischemic mainly centralize in vitro, and there is shortage of the data in vivo,here we use westen blotting and immunohistochemistry method to detect the expression of CYGB in the normal oxygen and the hypoxia-ischemia, systematically research the expression of CYGB and initially approach its expressing rule ,in order to offer the theory support for the etiopathogenesis and the clinic healing of the correlated disease about the Hypoxia-ischemia brain injury.[Objective] To explore the characteristics of expression of the cytoglobin in the brains of seven-day-old rats after Hypoxia-ischemia.[Methods] One hundred and thirty eight wistar rats of 7-day old were divided into 6 groups randomly. Five study groups,including study (0 hour),study(4 hour),study(12 hour),study(24 hour),study(48 hour),and control group(normoxic group). The brain tissues were taken at 0 hour,4 hours,12 hours,24 hours,48 hours after the hypoxic-ischemia injury of brain,and western blotting and immunohistochemistry method were used to detect the expression of CYGB .[Results] Immunohistochemistry showed that cytoglobin was located in the plasma of the cortex,thalamencephalon and hippocamp ,the number and staining strength of cytoglobin was enhanced in the hypoxic groups in comparison with the normoxic group,especially the group 12-hour, 24-hour ,48-hour. Western blotting showed significantly stronger expression of protein of cytoblobin in the every hypoxic group than in the normoxic group(all P<0.000). The expression of cytoglobin was up-regulated more significantly in the hypoxic 12-hour group than in the hypoxic 0- ,4-hour groups,and the hypoxic 24-,48-hour groups more significantly than the hypoxic 12-hour group. however,without a significant difference between the hypoxic 0-and 4-hour groups(P>0.05),and the same as the difference between the hypoxic 24- and 48-hour(P>0.05) .[Conclusions] The expression of CYGB in brain tissue increased rapidly after the hypoxic-ischemi brain injury of newborn rats,suggesting that CYGB may have important function in the protection process of hypoxic-ischemic brain injury.