Lipocortin-1 inhibits NMDA receptor-mediated neuronal damage in the striatum of the rat.
Lipocortin-1 (annexin-1), an endogenous phospholipid and calcium binding protein, has been shown to significantly attenuate the damage produced by focal cerebral ischaemia in the rat. In the present study we have therefore investigated its effect on N-methyl-D-aspartate (NMDA) induced neuronal damage. Unilateral intrastriatal infusion of a potent and selective NMDA agonist, cis-2,4-methanoglutamate (MGlu), induced an extensive lesion of the striatum in the rat, which was inhibited (greater than 80%) by prior injection of MK801 (4 mg/kg, i.p.). Infusion of 1.2 micrograms of an active fragment of lipocortin-1 (N-terminal 1-188 aa) immediately after MGlu significantly reduced the extent of damage by 44.2 +/- 8.0%. In contrast, infusion of 3 microliters of neutralizing anti-lipocortin-1 antibody with MGlu increased lesion size by 158.9 +/- 22.0%. These findings indicate that the damage produced by intrastriatal infusion of MGlu is mediated by the NMDA receptor. Lipocortin-1 fragment markedly attenuated, and the neutralizing antibody increased, this NMDA mediated neuronal damage. These observations may explain the neuroprotective action of lipocortin following cerebral ischaemia.
Black
M D
MD
Department of Experimental Neurology, University of Manchester, UK.
Carey
F
F
Crossman
A R
AR
Relton
J K
JK
Rothwell
N J
NJ
D000818:Animals; D017302:Annexins; D002135:Calcium-Binding Proteins / Q000494:pharmacology*; D003342:Corpus Striatum / Q000187:drug effects* / Q000473:pathology; D016291:Dizocilpine Maleate / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005971:Glutamates / Q000494:pharmacology; D008297:Male; D009410:Nerve Degeneration / Q000187:drug effects*; D009474:Neurons / Q000187:drug effects* / Q000473:pathology; D010446:Peptide Fragments / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D016194:Receptors, N-Methyl-D-Aspartate / Q000502:physiology*
D017302:Annexins; D002135:Calcium-Binding Proteins; D005971:Glutamates; D010446:Peptide Fragments; D016194:Receptors, N-Methyl-D-Aspartate; C066302:2,4-methanoglutamate; D016291:Dizocilpine Maleate