Appearance of white blood cells in the cerebrospinal fluid of rats following intravenous injection of lipopolysaccharide.

: Intravenous injection of lipopolysaccharides (LPS), even in very low amounts (5 micrograms), leads to the appearance of white blood cells (WBC) in rat cerebrospinal fluid (CSF). The number of WBC is dependent on either dose of LPS or time of injection. The population of WBC consists of monocytes, granulocytes and lymphocytes, while red blood cells are not detectable. These findings support the pathogenetic role which LPS may play in the course of bacterial meningitis mostly in terms of pleocytosis and raised protein content in the CSF.