ACTIVATION OF THE HPA AXIS BY IMMUNE INSULTS - ROLES AND INTERACTIONSOF CYTOKINES, EICOSANOIDS, AND GLUCOCORTICOIDS

It is now well established that challenges to the immune system (e.g., infection, inflammation) initiate diverse changes in neuroendocrine f unction, the most overt of which is activation of the hypothalamo-pitu itary-adrenocortical (HPA) axis. The glucocorticoids that are released as a consequence fulfill a vital role in the maintenance of homeostas is that is effected in part through their ability to quench the immune /inflammatory response and thereby prevent them accelerating to a poin t where they become hazardous to the host. This article discusses the putative mechanisms by which immune insults stimulate the HPA axis, wi th particular reference to the roles and interactions of the interleuk ins, eicosanoids and glucocorticoids.