ISSN:
1471-4159
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Medicine
Notes:
Abstract: We investigated the role of polyamines and their regulatory enzyme ornithine decarboxylase in N-Methyl-D-aspartate-induced excitotoxicity in embryonic chick retina. N-Methyl-D-aspartate (200 μM) produced an early increase in ornithine decarboxylase activity, putrescine concentration, and Ca2+ entry, leading to selective neuronal death by 30 min. This response was attenuated by the ornithine decarboxylase inhibitor α-difluoromethylornithine and the N-methyl-D-aspartate receptor antagonist 5-aminophosphonovaleric acid. Exogenous putrescine increased intracellular putrescine and spermine levels and reversed neuroprotection by α-difluoromethylornithine, but not by 5-aminophosphonovaleric acid. N-Methyl-D-aspartate-receptor stimulation of putrescine/polyamine synthesis mediates abnormal Ca2+ entry and acute excitotoxic neuronal death. Postreceptor inhibition of the ornithine decar-boxylase/polyamine cascade by α-difluoromethylornithine may provide neuroprotection against N-methyl-D-aspartate-induced excitotoxicity.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1471-4159.1993.tb05858.x
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