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In order to identify possible peripheral markers of illegal treatments with growth-promoting agents in veal calves, β-adrenergic receptor ( β-AR) and glucocorticoid receptor (GR) concentrations were measured in lymphocytes of 12 male Friesian crossbred calves (six controls and six treated). The animals received a cocktail of anabolic and re-partitioning agents [17 β-oestradiol: 3 × 10 mg intramuscular (i.m.) doses at 17-day intervals; dexamethasone sodium phosphate: 4 mg/day for 6 days and 5 mg/day for six further days dissolved in milk; and clenbuterol: 20 μg/kg/day dissolved in milk for the last 40 days before slaughter]. Blood samples were collected by venipuncture at different time points and lymphocytes were isolated by density gradient centrifugation. Lymphocyte β-AR and GR levels were measured by binding assays. Treatment with re-partitioning agents caused a significant down-regulation of lymphocyte β-ARs 19 days after the beginning of clenbuterol administration and at day 55 (after dexamethasone withdrawal, just before slaughter). This phenomenon was partially reversed at day 50, after dexamethasone administration, at which time a significant decrease in GR concentrations also occurred. For both types of receptors, no significant changes in the dissociation constant values were observed at any time point. Lymphocytes express measurable concentrations of β-ARs and GRs and the measurement of receptor levels highlights the fluctuation of receptor expression due to the dynamic interaction of the drugs used in combination. Lymphocyte receptor determination could therefore be included in a battery of biological assays to detect illegal treatments with anabolic agents in veal calves in the light of a multivariate approach. [ABSTRACT FROM AUTHOR]

The article presents a research related to the effects of short term transportation and housing on hormonal levels and on lymphocyte glucocorticoid and β-andrenergic receptor levels in beef calves. Thirty-two male calves were blood sampled at 6, 12 and 18 months before and after transportation to the slaughterhouse. Hormone levels were determined by radioimmunoassay. The study confirms the activation of the hypothalamic-pituitary-adrenal axis system in short-term transported calves.