| Abstract: | The effects of three glucocorticoids (steroids; hydrocortisone, prednisolone and dexamethasone) on cell mediated hypersensitivity (type IV) reactions in rats and mice were studied. All the steroids inhibited both the induction and the effector phases of type IV reaction induced by sheep red blood cells (SRBC) in mouse footpads. The local graft vs host reaction induced by lymphocytes from Brown Norway rats into the footpads of (Lewis x Brown Norway) F1 rats was also clearly inhibited by steroids. The inhibitory action of steroids on footpad reactions induced by SRBC was clearly prevented by pretreatment with non-corticoidal steroids (17 alpha-methyltestosterone, androstenedione and progesterone). The release of lymphokines, macrophage chemotactic factor (MCF) and skin reactive factor (SRF) was inhibited by each steroid at a high concentration. Moreover, steroids inhibited the activity of MCF in vitro and SRF in vivo. |
