title: Melatonin Reduces Hypoglycemia-Induced Neuronal Death in Rats.
abstract: Melatonin, N-aceyl-5-methoxytryptamine, is the main secretory product of the pineal gland and has neuroprotective effects on several brain injuries, including ischemic stroke. In the present study, we hypothesized that exogenous melatonin may decrease hypoglycemia-induced neuronal death through the prevention of superoxide generation. To test our hypothesis, hypoglycemia was induced by injecting human insulin (10 U/kg, i.p.) in rats. Melatonin injection was started immediately after hypoglycemia (10 mg/kg, i.p.). The first melatonin injection was performed at the end of a 30-min isoelectric EEG period. The second and third injections were administered at 1 and 3 h after the first injection. Reactive oxygen species generation, as detected by dihydroethidium staining, was significantly reduced by melatonin treatment. Neuronal injury was reduced by the treatment of melatonin in the hippocampal CA1 and dentate granule cells. Microglia activation was robust in the hippocampus after hypoglycemia, which was almost completely prevented by melatonin treatment. Hypoglycemia-induced cognitive impairment was also significantly prevented by melatonin treatment. The present study suggests that melatonin has therapeutic potential to prevent hypoglycemia-induced brain injury.
authors.affiliation: Department of Neurology, University of California, San Francisco, Calif., USA.
authors.forename: Jin Hee
authors.initials: JH
authors.lastname: Kim
authors.forename: Byung Hoon
authors.initials: BH
authors.lastname: Yoo
authors.forename: Seok Joon
authors.initials: SJ
authors.lastname: Won
authors.forename: Bo Young
authors.initials: BY
authors.lastname: Choi
authors.forename: Bo Eun
authors.initials: BE
authors.lastname: Lee
authors.forename: In Yeol
authors.initials: IY
authors.lastname: Kim
authors.forename: Ara
authors.initials: A
authors.lastname: Kho
authors.forename: Song Hee
authors.initials: SH
authors.lastname: Lee
authors.forename: Min
authors.initials: M
authors.lastname: Sohn
authors.forename: Sang Won
authors.initials: SW
authors.lastname: Suh