Induction of enhanced responsiveness of human articular chondrocytes to extracellular ATP by tumour necrosis factor-α

1. We have observed previously that extracellular ATP acting at P 2 -purinoceptors promotes the production of prostaglandin E 2 by human articular chondrocytes, and that this response is enhanced synergistically by interleukin-1β. Since other cytokines that influence the metabolism of articular cartilage may have a similar effect, we have investigated whether tumour necrosis factor-α also modulates the stimulation of the production of prostaglandin E 2 in these cells by ATP. 2. Tumour necrosis factor-α enhanced the response of cultured human articular chrondrocytes to a maximally stimulating concentration of ATP (100 μmol/l)