CAMP IS NOT INVOLVED IN INTERLEUKIN-1-INDUCED INTERLEUKIN-6 RELEASE FROM HUMAN ASTROCYTOMA-CELLS

We have previously shown that activation of the phosphatidyl-inositol/ phospholipase C pathway could induce interleukin 6 (IL-6) release from U373MG human astrocytoma cells. We also found that, although interleu kin 1 beta (IL-1 beta) did not activate phosphatidylinositol turnover, it induced a robust release of IL-6. In the present study, we examine d the role of adenylate cyclase/cyclic 3',5'-adenosine monophosphate ( cAMP) pathway in IL-6 release. Agents,which mimicked (dibutyryl cAMP) or stimulated (isoproterenol and forskolin) cAMP formation were found to induce IL-6 release and their effects could be potentiated by 3-iso butyl-1-methylxanthine (IBMX), a phosphodiesterase inhibitor. On the o ther hand, in spite of its robust action on IL-6 release, IL-1 beta di d not stimulate cAMP formation. Other possible signal transduction mec hanisms involved in IL-1 beta-induced IL-6 release are discussed.