OBJECTIVE: Heparins may exert several anti-inflammatory actions. This study investigated the impact of low molecular weight heparin (LMWH) on tumor necrosis factor (TNF)-alpha-provoked leukocyte rolling, adhesion and extravascular accumulation. MATERIALS AND METHODS: Leukocyte-endothelium interactions and tissue accumulation of leukocytes were induced by TNF-alpha in Balb/c mice and analyzed by the use of intravital microscopy in the mouse cremaster muscle microcirculation. RESULTS: We observed that administration of 5000 units/kg of LMWH, but not 50 and 500 units/kg, markedly reduced TNF-alpha-induced leukocyte rolling, adhesion and tissue infiltration. Notably, when LMWH was given after TNF-alpha only leukocyte rolling was reduced and no effect was observed on firm adhesion of leukocytes. CONCLUSIONS: Taken together, these findings indicate that LMWH inhibits TNF-alpha-induced leukocyte accumulation by inhibiting the rolling adhesive interaction which may help explain the anti-inflammatory effects of LMWH.
OBJECTIVE:Heparins may exert several anti-inflammatory actions. This study investigated the impact of low molecular weight heparin (LMWH) on tumor necrosis factor (TNF)-alpha-provoked leukocyte rolling, adhesion and extravascular accumulation. MATERIALS AND METHODS: Leukocyte-endothelium interactions and tissue accumulation of leukocytes were induced by TNF-alpha in Balb/c mice and analyzed by the use of intravital microscopy in the mouse cremaster muscle microcirculation. RESULTS: We observed that administration of 5000 units/kg of LMWH, but not 50 and 500 units/kg, markedly reduced TNF-alpha-induced leukocyte rolling, adhesion and tissue infiltration. Notably, when LMWH was given after TNF-alpha only leukocyte rolling was reduced and no effect was observed on firm adhesion of leukocytes. CONCLUSIONS: Taken together, these findings indicate that LMWH inhibits TNF-alpha-induced leukocyte accumulation by inhibiting the rolling adhesive interaction which may help explain the anti-inflammatory effects of LMWH.
Authors: Heloísa Antoniella Braz-de-Melo; Sara Socorro Faria; Gabriel Pasquarelli-do-Nascimento; Igor de Oliveira Santos; Gary P Kobinger; Kelly Grace Magalhães Journal: Front Med (Lausanne) Date: 2021-04-23