Induction of tumor necrosis factor-alpha mRNA in the brain after peripheral endotoxin treatment: comparison with interleukin-1 family and interleukin-6.

The constitutive expression of tumor necrosis factor-alpha (TNF alpha) mRNA and its induction (60 min later) by peripheral injection of Escherichia coli lipopolysaccharide (2 mg/kg i.p.) was demonstrated by polymerase chain reaction (PCR), in the pituitary and hypothalamus but not in the striatum or hippocampus of the rat. The pattern of TNF alpha mRNA induction is different from that observed for mRNAs of IL-1 alpha and IL-1 beta, IL-1ra and IL-6 respectively. This demonstration of the induction of TNF alpha in the brain may contribute to our understanding of the central effects of TNF alpha in fever and anorexia.