Induction of angiogenesis in the beta-amyloid peptide-injected rat hippocampus.
Angiogenesis, the formation of new capillary blood vessels, has been studied following the stereotaxic injection of beta-amyloid peptide (Abeta1-42) into rat hippocampus. Immunohistochemical analysis for laminin showed that neovascularization was only slightly increased, relative to control, in the hippocampus 1 day post-Abeta1-42 injection. However, 7 days following peptide injection neovascularization was markedly up-regulated (by 2.2-fold) compared to control. Immunoreactivity for the angiogenic stimulatory agent vascular endothelial growth factor (VEGF) was also significantly increased in the hippocampus 7 days after Abeta1-42 injection. Double immunofluorescence staining demonstrated that the increased level of VEGF immunoreactivity was localized to both astrocytes and microglia, suggesting inflammatory responses contributed to angiogenesis. The findings of beta-amyloid stimulated angiogenesis and the involvement of peptide-induced inflammatory processes may have relevance to the pathology of Alzheimer's disease.
Zand
Ladan
L
Department of Pharmacology and Therapeutics, Faculty of Medicine, The University of British Columbia, 2176 Health Sciences Mall, Vancouver, BC, V6T 1Z3, Canada.
Ryu
Jae K
JK
McLarnon
James G
JG
D016229:Amyloid beta-Peptides / Q000008:administration & dosage*; D000818:Animals; D006624:Hippocampus / Q000098:blood supply* / Q000187:drug effects*; D008297:Male; D018919:Neovascularization, Physiologic / Q000187:drug effects* / Q000502:physiology; D010446:Peptide Fragments / Q000008:administration & dosage*; D051381:Rats; D017207:Rats, Sprague-Dawley
D016229:Amyloid beta-Peptides; D010446:Peptide Fragments; C075222:amyloid beta-protein (1-42)