| Abstract: | The effects of corticosteroids on the chemiluminescence response of bovine phagocytic cells were determined both in vitro and in vivo. The in vitro addition of hydrocortisone or dexamethasone had no significant effect on the chemiluminescence response of leukocytes in a whole blood or purified polymorphonuclear leukocyte (PMN) population. Cattle that received a single 20 mg dose of dexamethasone or three 20 mg doses of dexamethasone (given 24 hours apart) demonstrated the expected effects on the bovine leukogram (leukocytosis, neutrophilia, lymphopenia, eosinopenia, and monocytosis) and also demonstrated the expected suppressive effect on lymphocyte response to phytohemagglutinin (PHA). However, neither a single nor multiple dexamethasone treatment(s) had an effect on the chemiluminescence response of phagocytes in whole blood, but significantly enhanced the chemiluminescence response of the purified PMN leukocyte population. There was no significant difference between the two dexamethasone treatment groups in either the degree or duration of the effects observed in the chemiluminescence or lymphocyte response assays. |
