title: Dexamethasone prevents hypoxic-ischemic brain damage in the neonatal rat.
abstract: Glucocorticoid therapy is frequently used in perinatology and neonatology for its beneficial pulmonary effects. We investigated the influence of neonatal glucocorticoid administration on brain damage caused by a concurrent episode of cerebral hypoxia-ischemia. Various doses of dexamethasone in several treatment schedules were administered to 7-d-old rats that were also subjected to unilateral cerebral hypoxia-ischemia. In 79% of control rats, a large unilateral cerebral infarction occurred, whereas all rats pretreated with dexamethasone in doses of 0.01 to 0.5 mg/kg/d for 3 d had no infarction (p less than 0.001). The neuroprotective effect of dexamethasone pretreatment was dose- and time-dependent. Treatment with dexamethasone after the insult or with lower doses before the insult did not prevent infarction. The neuroprotective effect was not immediate: single doses 0 to 3 h prehypoxia were not effective but a single dose 24 h before hypoxia-ischemia prevented cerebral infarction. The results demonstrate that glucocorticoid administration in the neonatal period, even in low doses, protects the brain during subsequent periods of hypoxia-ischemia.
authors.affiliation: Department of Pediatrics, Hospital for Sick Children, Toronto, Ontario, Canada.
authors.forename: J D
authors.initials: JD
authors.lastname: Barks
authors.forename: M
authors.initials: M
authors.lastname: Post
authors.forename: U I
authors.initials: UI
authors.lastname: Tuor
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001921:Brain / Q000187:drug effects* / Q000473:pathology; D001930:Brain Injuries / Q000517:prevention & control; D002545:Brain Ischemia / Q000517:prevention & control; D003907:Dexamethasone / Q000008:administration & dosage / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D002534:Hypoxia, Brain / Q000517:prevention & control; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D003907:Dexamethasone