title: The effect of the treatment of high-dose methylprednisolone on Na(+)-K(+)/Mg(+2) ATPase activity and lipid peroxidation and ultrastructural findings following cerebral contusion in rat.
abstract: BACKGROUND
  Although use of corticosteroid in the management of head trauma has caused a great deal of controversy, corticosteroids have long been an adjunct in the management of severe closed head injury. The glucocorticoid steroid methylprednisolone (MP) has been proven to have significant antioxidant effect when administered in an antioxidant-high dose after central nervous system injury.
  
  
  METHODS
  The sodium-potassium activated and magnesium dependent adenosine-5'-triphosphatase (Na(+)-K(+)/Mg(+2) ATPase EC.3.6.1.3.) activity, lipid peroxidation, and early ultrastructural findings were determined during the immediate posttraumatic period in rats. Mechanical brain injury was produced when a calibrated weight-drop device is allowed to fall on the skull's convexity over the right hemisphere, 1 to 2 mm lateral from the midline. In group I, rats were used to determine Na(+)-K(+)/Mg(+2) ATPase activity, the extent of lipid peroxidation, by measuring the level of malondialdehyde content and normal ultrastructural findings in two different brain areas (cerebral cortex and brain stem). In group II, physiologic saline was administered right after trauma in the same amount as methylprednisolone. In group III rats, methylprednisolone (30 mg/kg) was administered intravenously right after trauma.
  
  
  RESULTS
  Na(+)-K(+)/Mg(+2) ATPase activity significantly decreased in the cerebral cortex and in brain stem within 2 hours after trauma (p < 0.05). There was significant difference in malondialdehyde content between groups II and III (p < 0.05). Methylprednisolone treatment reduced malondialdehyde content and induced the recovery of Na(+)-K(+)/Mg(+2) activity.
  
  
  CONCLUSIONS
  These data suggest that inactivation of Na(+)-K(+)/Mg(+2) ATPase is closely correlated to changes of lipid peroxidation and the alteration of the ultrastructural findings in the early phases after head trauma. The glucocorticoid steroid methylprednisolone has been proven to have significant effect in activation of Na(+)-K(+)/Mg(+2) ATPase with significant reduction of malondialdehyde content.
authors.affiliation: Department of Neurosurgery, Cukurova University, School of Medicine, Balcali Adana, Turkey.
authors.forename: F
authors.initials: F
authors.lastname: Ildan
authors.forename: S
authors.initials: S
authors.lastname: Polat
authors.forename: A
authors.initials: A
authors.lastname: Oner
authors.forename: T
authors.initials: T
authors.lastname: Isbir
authors.forename: E
authors.initials: E
authors.lastname: Cetinalp
authors.forename: M
authors.initials: M
authors.lastname: Kaya
authors.forename: A
authors.initials: A
authors.lastname: Karadayi
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology* / Q000627:therapeutic use*; D001921:Brain / Q000187:drug effects* / Q000201:enzymology / Q000648:ultrastructure; D001930:Brain Injuries / Q000188:drug therapy / Q000201:enzymology / Q000378:metabolism*; D017301:Ca(2+) Mg(2+)-ATPase / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D015227:Lipid Peroxidation / Q000187:drug effects*; D008297:Male; D008775:Methylprednisolone / Q000494:pharmacology* / Q000627:therapeutic use; D051381:Rats; D017208:Rats, Wistar; D000254:Sodium-Potassium-Exchanging ATPase / Q000187:drug effects / Q000378:metabolism*
chemical_list: D000893:Anti-Inflammatory Agents; D017301:Ca(2+) Mg(2+)-ATPase; D000254:Sodium-Potassium-Exchanging ATPase; D008775:Methylprednisolone