Amyloid-beta(25-35) impairs memory and increases NO in the temporal cortex of rats.
beta-Amyloid plays an important role in the neurodegeneration process of Alzheimer's disease (AD), but its neurotoxic mechanisms are not clear. It has been associated with the increase of oxidative stress and cognitive impairment because the beta-amyloid peptide 25-35 (Abeta((25-35))) has the critical neurotoxic properties of the full-length Abeta(1-42). Our present study shows the role of Abeta((25-35)) when injected into the temporal cortex on the nitric oxide pathways, 3-nitrotyrosine, neuronal death, and the spatial memory of rats 1 month after the injection. Our data showed that Abeta((25-35)) increases oxidative stress, causes neuronal damage, and decreases spatial memory in rats. Notably, the injection of the fraction Abeta((25-35)) caused an increase of nNOS and iNOS immunoreactivity in the temporal cortex and hippocampus. We demonstrated a significant increase of reactive astrocytosis, which was accompanied by neuronal damage in the temporal cortex and hippocampus of rats injected with Abeta((25-35)). These data suggest that the fraction Abeta((25-35)) injected into the temporal cortex might contribute to understanding the role of nitric oxide on the biological changes related to the neuropathological progression and the memory impairment in AD.
Limón
I Daniel
ID
Laboratorio de Neurofarmacología, Facultad de Ciencias Químicas, Benemérita Universidad Autónoma de Puebla, Puebla, Mexico.
Díaz
Alfonso
A
Mendieta
Liliana
L
Chamorro
Germán
G
Espinosa
Blanca
B
Zenteno
Edgar
E
Guevara
Jorge
J
D016229:Amyloid beta-Peptides; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D008297:Male; D018782:Maze Learning / Q000187:drug effects; D008569:Memory Disorders / Q000139:chemically induced* / Q000473:pathology*; D009569:Nitric Oxide / Q000378:metabolism*; D052248:Nitric Oxide Synthase Type I / Q000378:metabolism; D010446:Peptide Fragments; D051381:Rats; D017208:Rats, Wistar; D016622:Silver Staining / Q000379:methods; D013028:Space Perception / Q000187:drug effects; D013702:Temporal Lobe / Q000187:drug effects / Q000201:enzymology*
D016229:Amyloid beta-Peptides; D005904:Glial Fibrillary Acidic Protein; D010446:Peptide Fragments; C074636:amyloid beta-protein (25-35); D009569:Nitric Oxide; D052248:Nitric Oxide Synthase Type I