Neuroprotective effects of hypothermia and erythropoietin after perinatal asphyxia in newborn rats

Objective: Evaluation of neuroprotective effects of hypothermia, erythropoietin and their simultaneous use after perinatal asphyxia in newborn rats. Method: Histerectomy was performed to Wistar female rats on the last day of gestation. Perinatal asphyxia was induced by submersion of uterus containing pups in saline for 15 min. After resuscitation, pups were randomized into 4 groups, 15 animals in each: G1 - asphyxia; G2 - asphyxia + hypothermia (rectal temperature 33 degrees C for 1 h); G3 - asphyxia + erythropoietin (Darbepoetin-alpha 2.5 mu g, intraperitoneally) and G4 - asphyxia + erythropoietin + hypothermia. Pups were sacrificed on 7th day of life and histopathological analysis of hippocampus was performed. Results: Measure of damage to dorsal, ventral and entire hippocampus was significantly lower in groups G2, G3 and G4 than in group G1 (p similar to 0.00; respectively). Measure of damage to hippocampus in group G4 was significantly lower than in group G2 (p = 0.029). Conclusions: This study demonstrates that simultaneous use of hypothermia and erythropoietin has more expressed neuroprotective effects than sole use of hypothermia after perinatal asphyxia in newborn rats.