In vivo and in vitro effects of three glucocorticoids on blood leukocyte chemotaxis in the dog.

The effects of three glucocorticoids on random migration (RM) and oriented migration (OM) of dog blood leukocytes either from dogs treated in vivo (at therapeutic dosage regimen) or leukocytes treated in vitro (at pharmacological concentrations), were investigated using an agarose gel technique. After in vivo treatment, methylprednisolone sodium succinate (MPSS) produced a stimulation of both RM and OM in the three treated dogs. Dexamethasone produced a stimulation of both RM and OM in the three treated dogs. Dexamethasone produced a stimulation of these parameters in all but one of the three treated dogs, but the difference was not statistically significant. After in vitro treatment of leukocytes from eight dogs, MPSS significantly stimulated OM. Dexamethasone was without significant effect except at a higher than therapeutic concentration (0.5 micrograms/ml), for which RM was stimulated. Hydrocortisone sodium succinate was without statistically significant effect. Under no conditions, except after suprapharmacological concentrations, did glucocorticoids inhibit RM or OM.