EN
The aim of the study was to determine the effect of dexamethasone injections on changes in seminal plasma testosterone and oestradiol-17b concentration and biochemical characteristics in stallions following endotoxin administration. Three clinically healthy stallions were infused intravenously with endotoxin (LPS) from Escherichia coli 055:B5 at a dose of 0.3 mg/kg b.w.; while four stallions were treated with dexamethasone (0.069 mg/kg b.w., IM) 10 min before the administration of LPS. Endotoxin administration elicited (24h-9 weeks after LPS administration) a significant (P < 0.05) decrease in seminal plasma testosterone (T) and an increase in oestradiol-17β E₂β concentration. Administering endotoxin also influenced the seminal plasma biochemical components including total protein (TPR), albumin (ALB), total cholesterol (CHOL) concentration, and aspartate aminotransferase (AST) activity. A significant (P < 0.05) increase in TPR, ALB, and AST was noted. Dexamethason administration (DEX) had a different effect on endotoxin and induced testosterone and oestradiol-17β changes in the seminal plasma and biochemical quality of the stallion’s semen. DEX treatment had no influence on T, E₂β. The positive influence of DEX was noticed in TPR and AST. The negative influence of administering LPS+DEX in the group of stallions which only received LPS was noted particularly in ALB and CHOL.