Effects Of Resuscitation With 100% Oxygen Or Room Air On Renal Tubular Epithelial Cell Of Asphyxial Neonatal Rat

ObjectiveTo establish an animal model of asphyxial neonatal rat and compare the effects of resuscitation with 100%oxygen and resuscitation with room air on the ultrastructure and the apoptosis on the kidney of asphyxial neonatal rats,in order to provide a scientific basis for clinical choice to resuscitation.MethodThirty 7-day aged SD rats were randomly divided into there groups:RA group (n=10) resuscitated with room air,PO group(n=10) resuscitated with 100%oxygen, N group(n=10) used as the control group,which only underwent sham operation. Each group was divided into three sub-groups:24h group(n=5),which was killed 24h after resuscitation;72h group(n=5),which was killed 72h after resuscitation.An animal model of asphyxial neonatal rat was established,the asphyxial pups were resuscitated with 100%oxygen or room air for 30min according to different groups.Then the pups were killed at 24h or 72h after the resuscitation.The kidneys were removed for histological,immunohistochemical and apoptosis examination.The positive units(PU) and apoptotic cells were evaluated with a image analysis system. Transmission electron microscope was used to investigate the ultrastructural changes of the proximal and distal renal tubule and renal glomerular membrane.ResultsHistologically,an edematous of epithelial cells and narrowing of tubular cavea were found in proximal and distal renal tubule in both PO and RA group.It seemed no notable difference between the two groups.The pathological changes mentioned above were more serious in 24h sub-group than that in the corresponding 72h sub-group.The glomerular structure could be clearly seen.Ultrastructurally,the swelling and vacuolization of mitochondria in proximal and distal renal tubule and the degree of collapse crista in the PO group were more marked than that in corresponding RA group,especially in the 24h sub-group.The ultrastructure of 72h sub-group in both PO and RA group was improved obviously as compared with the corresponding 24h sub-group.The expression of caspase-3 was higher in PO group than in RA group (p＜0.01).Likewise,24h sub-group had a higher expression of caspase-3 than corresponding 72h sub-group(p＜0.01).Though TUNEL technique,RA group had lower apoptotic index than PO group(p＜0.01),while a similar difference was not found in the sub-groups(p＞0.05).ConclusionThe mitochondria of PO group showed more severe pathological changes than that of RA group.Compared with RA group,the expression of apoptotic enzymes such as caspase-3 and apoptotic index(AI) were higher in the PO group.The pathological changes of mitochondria such as vacuolization and rupture of cristae were milder in 72h sub-group as compared to relative 24h sub-group, indicating that impaired mitochondria could be repaired through self-regeneration.