The cytokines, tumour necrosis factor (TNF)-alpha, interleukin (IL)-1 beta, and IL-6, have been found in the human central nervous system. Recent studies have demonstrated that murine astrocytes produce these cytokines when induced with lipopolysaccharide endotoxin (LPS). The present study investigates the kinetics of TNF-alpha, IL-1 beta, and IL-6 production by normal adult human astrocytes when exposed to LPS.