Resumen de Comparative in vivo and in vitro models to approach the cellular basis of endotoxic shock. The role of sinusoidal liver cells

Raffaella Pagani Balletti, María Teresa Portolés Pérez, Rosa María Arahuetes Portero, M.J. Ainaga, Celia Machin, María del Carmen Rúa Rodríguez

• During endotoxic shock, the liver exerts a lipopolysaccharide (LPS) clearance function with the participation of both parenchymal and sinusoidal cells. Liver damage could be caused by LPS direct action, hypoxia and/or inflammatory mediators released by Kupffer cells. The aim of this study is to establish an experimental model that could allow us to understand the direct E. coli O1 1 l:B4 LPS action on sinusoidal cells. A comparative study was carried out, in vivo and in vitro, using either a rat reversible endotoxic shock model or sinusoidal cell cultures. The LPS was found to induce important and similar morphological alterations both in vivo and in vitro, specially in Kupffer cells. These cells present mitochondrial damage, nuclear membrane swelling, and increased number of phagosomes, including lamellar bodies. An immunocolloidal gold technique shows, in vitro, the LPS mainly located on Kupffer cell membrane and in phagosomes. The LPS binding to membrane, as a primary step of Kupffer cell activation, increases the phagocytosis. This effect could be related to a decrease of fluidity on the externa1 membrane portion.