EFFECT OF HYPEROXIA ON NEWBORN RATS OF HYPOXIC ISCHEMIC BRAIN DAMAGE

To explore the pathologic and DNA changes in the brain of the hypoxic ischemic brain damage(HIBD)newborn rats after exposed to high oxygen for long time.The pathologic changes were observed by brain general examination and light microscope after HIBD newborn rats were exposed to pure oxygen for 48 hours.The electrophoresis of DNA extracted from brain tissue was used to detect injured DNA Results Shoused that fter HIBD newborn rats were exposed to oxygen,left hemisphere weight and weight dificit,degree of the left cerebral general damage improved slightly on day 5, but there were on differences form on oxygentreated control group.The death rate of oxygen treated group was higher than control group which parameters were 11.5% and 4.2% respectively,but there was on signifincant difference also.Observed by light microscope on day 5 after oxygentreated,the degree of the brain admage was less severe than untreated control group,but statistical analysis could not been made.After newborn rats were hypoxic ischemic for 48 hours,smears and “ladders”of DNA extracted from cortex,hippopcampus,striatum and thalamus appeared on electrophoresis indicating there were sacrified on the same day,the appearance of the electrophoresis of extracted DNA from the brain had no significant changes compared with untreated control group in the same template.Therefose exposure HIBD newborn rats to pure oxygen for 48 hours could not improve brain pathologic and DNAdamage,but the death rate increased. (Original article in page 121)