Correlation Among Trx, NOS And Apoptosis Of Neonate Rats After Undergoing Hypoxic-ischemic Brain Damage And Intervention Effect Of Dexamethasone

Objective: To observe, in different period, the morphological changes, the expression of Trx and the production of NOS of brain cells of neonate rats after undergoing hypoxic-ischemic brain damage (HIBD), to probe into the correlation between Trx and apoptosis, NOS and apoptosis. and Trx and NOS, in order to put forward experimental and theoretical foundation for HIBD. To observe the role of Dexamethasone playing in apoptosis, Trx and NOS, aiming at disclosing the correlation between Trx and NOS.Method: a total of 45 SD rats, female or male, with the birth weight of 12 to 18 gram were divided into blank controlling group, test group and medication administration group, each group were divided into 3groups according to hypoxic ischemic time, including 3 h group, 24h group and 72 h group. The animals in test group were put into the hypoxic environment containing 8% 02 after blotting left common carotid artery to make animal model of hypoxic-ischemic brain damage. There are 5 rats in each group. The brain tissue of neonates rats of all the groups were observed on the pathologic changes, marked by HE stain, and terminal-deoxynucleotidyl transferase mediated nick end labeling (TUNEL) , under light microscopic, and were tested the expression of Trx by rtPCR, content of NOS by ultraviolet spectrophotometer, and apoptosis cells by TUNEL. Dexamethasone was injected into abdominal cavity of the rats in medication administration group 24 hours before hypoxic ischemia.Result: apoptotic cell can be observed, Trx and NOS can be detected in normal brain tissue. Apoptosis increased after 3 hours of hypoxic ischemia, and up to the highest after 24 hours of hypoxic ischemia, and decreased after 72 hours of hypoxic ischemia, and all of the numbers in test group and medication administration group are higher significantly in contrast with controlling group. Trx also raised after 3hours of hypoxic ischemia, and up to the highest after 24 hours of hypoxic ischemia, and decreased after 72 hours of hypoxic ischemia, and in contrast with that of controlling group, there is a significant difference among them. The change tendency of NOS is the same as apoptosis and Trx. There is not correlation among apoptosis, Trx and NOS in HIBD. Dexmethasome can reduce apoptosis, lower the expression of Trx and the production of NOS. There is a moderate correlation among apoptosis, Trx and NOS. Subjects in medication administration group were administered dexmethasome 24 hours before the operation mentioned above. While animals in control were cut the skin of neck only. Conclusion: Trx and NOS were all increased after 3 hours of hypoxic ischemia, up to the highest after 24 hours of hypoxic ischemia, and lowered after 72 hours of hypoxic ischemia, which is in accord with the tendency of apoptosis, all of which, to a certain degree, put forward a theoretical basis for clinical intervention time and intervention study. There is not correlation among apoptosis, Trx and NOS in HIBD. After administrating dexmethasome 24 hours before HIBD, apoptosis, Trx and NOS all decreased, dexmethasome has a protective effect on HIBD.