EN
The effect of steroidal anti-inflammatory drug - dexamethasone on the changes of semen quality in stallions after endotoxin administration was studied. Three clinically healthy stallions were injected intravenously with endotoxin (LPS) from Escherichia coli 055:B5 at the dose of 0.3 µg/kg b.w.; while four stallions were treated with dexamethasone (0.069 mg/kg b.w., i.m.) 10 min before the administration of LPS. The administration of the endotoxin elicited a significant (P<0.05) decrease in the gel-free semen volume (GFSV), total spermatozoon motility (TSM), and spermatozoon concentration (SC). As regards to each of the morphological defects of the spermatozoa, the percentage of those with cytoplasmic droplets - droplet in distal (form 1), proximal and atypical position (defects 1-3); tail loops - single loop (form 4), double loop, loop of the end part of the tail, spiralling of the tail, and tail looped around the head (defects 4-8); two (or more) heads (form 13), and small ("dwarf") heads (form 15) were clearly higher in endotoxin treated stallions. The administration of dexamethasone (DEX) had a different effect on endotoxin-induced changes of the semen's quality. A positive influence of DEX was noticed in certain macro- and microscopic characteristics of the semen. There were noted smaller changes in TSM, SC, defects 1-3, form 1, and form 13. Dexamethason had no influence on GFSV. A negative influence of the administration of LPS+dexamethasone, in relation to the stallions treated only with LPS, was especially noticed in forms 4 and 15. This data suggest that the dexamethasone does not prevent and to a certain degree enhances an adverse influence of endotoxin on the semen quality in stallions.