EN
The aim of the study was to investigate the influence of Mycoplasma bovis challenge in calves on the alteration of acute- phase response (APR). The study was performed on twelve calves aged 4-8 weeks. The animals were divided into two equal groups: experimental and control. Calves in the experimental group were intratracheally challenged with pathogenic strain of Mycoplasma bovis, whereas controls received sterile physiological saline as placebo. The blood samples were collected before (1st d) and after the mycoplasma challenge (3, 5, 7 and 9th d). The following parameters were assayed in serum: acute phase proteins (APPs), i.e. haptoglobin (Hp) and amyloid A (SAA), and eicosanoids such as prostaglandin E₂ (PGE₂), prostaglandin F₂ₐ (PGF₂ₐ), leukotrien B4 (LTB₄), and tromboxan B₂ (TXB₂). In calves of experimental group, a significant increase in concentrations of Hp and SAA was observed when compared with the controls. A decrease in both APPs to the initial values, i.e. before the challenge, was noted on the 9th d of experiment. On the other hand, the inoculation of Mycoplasma bovis caused a significant increase of the examined eicosanoids, which maintained elevated during the whole study. The stimulation of synthesis of APPs and eicosanoids in response to the challenge with Mycoplasma bovis probably indicates the effective activation of APR under these conditions.