Oxidative stress and protein catabolism following dexamethasone and isoflupredone administration in Holstein calves

BACKGROUND: Glucocorticoids have several benefits in large animal medicine but apart from their benefits, there are several disadvantages attributed to the use of these drugs. Among the disadvantages, disturbance in protein metabolism is one of the side effects of glucocorticoids which has been investigated in human and laboratory animals. OBJECTIVES: There are no information regarding the effects of glucocorticoids on protein metabolism in large animals. Hence, the present experimental study was performed to evaluate the protein metabolism following glucocorticoids administration in Holstein calves. METHODS: Ten clinically healthy Holstein calves (6 to 8 months old) were assigned into 2 equal groups (n=5), containing Dexa and Iso. Dexamethasone (1 mg/kg, intramuscularly) and isoflupredone(1 mg/kg, intramuscularly) were administered in Dexa and Iso groups, respectively, on two consecutive days. Blood samples were taken at days 0 (1st drug administration), 1 (2nd drug dministration), 2, 3, 5 and 7, from all studied animals. Sera were assayed for total protein, albumin, globulin, serum amyloid A and haptoglobin. RESULTS: Serum amyloid A and haptoglobinexperience significant increase after administration of both drugs. Isoflupredone induced the synthesis of serum amyloid A and haptoglobin more than dexamethasone (p<0.05). Serum concentrations of total protein, albumin and globulin experienced significant decrease after infusion of dexamethasone and isoflupredone (p<0.05). Circulating levels of these proteins in Iso group were lower than Dexa one, significantly. CONCLUSIONS: Isoflupredone and dexamethasone can induce the protein catabolism. Furthermore, the concentrations of serum amyloid A and haptoglobin, as oxidative stress biomarkers, increased following both drugs administrations due to their oxidation effects on proteins. Finally, the effects of isoflupredone on the metabolism of proteins are significantly higher than dexamethasone in Holstein calves.