The role of cytokines in the production of prostacyclin and thromboxane in human mononuclear cells.

The aim of the present work was to study the regulatory effects of cytokines (TNF alpha, IL-1 beta and IL-2) on the production of the prostglandins (PGI2 and TXA2) from human mononuclear cells. Our major findings were: (1) TNF alpha, IL-1 beta and IL-2 were all able to induce PGI2 and TXA2 syntheses in mononuclear cells. (2) TNF alpha exerted a biphasic effect on prostaglandin production. The lower concentrations of TNF alpha enhanced prostaglandin synthesis while the higher concentrations did not. (3) TNF alpha had a positive effect after only a 30-minute incubation, whereas IL-1 beta and IL-2 required a 8-hour incubation to produce a significant effect. This suggests that the different mechanisms are involved in their actions. (4) The effects of cytokines on the production of PGI2 were greater than that on the production of TXA2. It is concluded that cytokines can not only regulate the production of prostaglandins but also change the pattern of their formation.