Intraperitoneal injection of platelet secretory products into mice increases macrophage uptake of oxidized low density lipoprotein.
Isr J Med Sci
; 29(8): 453-9, 1993 Aug.
Article
em En
| MEDLINE
| ID: mdl-8407271
ABSTRACT
Oxidized low density lipoprotein (LDL) (Ox-LDL) is taken up by macrophages at an enhanced rate and contributes to macrophage cholesterol accumulation and foam cell formation. Platelet secretory products have been shown to modulate the uptake of Ox-LDL by mouse peritoneal macrophages. This study is unique since mouse peritoneal macrophages were interacted with platelet conditioned medium (PCM, the supernatant that was obtained from collagen-treated washed human platelets) in the peritoneal cavity of the mice rather than in plastic dishes. Macrophages obtained from the peritoneal cavity of mice, 20 h after the injection of PCM (up to 30 micrograms of cholesterol/ml), demonstrated a substantial increment in the uptake of Ox-LDL. The effect of PCM demonstrated a dose- and time-dependent pattern. The cellular uptake of the lipoprotein, measured as the cellular Ox-LDL degradation and cholesterol esterification rates, was increased by up to 60% and 30% respectively in macrophages collected from PCM-injected mice in comparison to control mice. These effects were the result of PCM-induced increased affinity of Ox-LDL towards its receptor, and increased number of macrophage binding sites for Ox-LDL. Upon delipidation of PCM, only the protein fraction possessed the ability to increase the cellular uptake of Ox-LDL. Dialyzed PCM, which is deprived of low molecular weight substances, still expressed the stimulatory effect of PCM. Our results thus suggest that a protein-like factor that is secreted from activated platelets can increase in vivo the ability of macrophages to take up Ox-LDL, as was also previously shown in in vitro studies.
Buscar no Google
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Plaquetas
/
Fatores Biológicos
/
Ativação Plaquetária
/
Lipoproteínas LDL
/
Macrófagos
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Isr J Med Sci
Ano de publicação:
1993
Tipo de documento:
Article
País de afiliação:
Israel