Quantitation of glucocorticoid receptors in bovine skeletal muscle: Topographical distribution, sex effect and breed comparisons

The concentration of the cytosolic glucocorticoid receptor (GR) was determined in skeletal muscles of calves in order to study possible differences in individual muscles from different parts of the body as well as the influence of sex and breed. In male and female Simmental calves the topographical distribution of GR was similar: the lowest concentrations were seen in abdominal muscle, whereas in neck, shoulder and hindleg the GR concentrations were higher; this difference was more pronounced in male than in female calves. In general, female calves had about 2-fold higher GR concentrations than males. The cytosolic cortisol concentrations were differing neither between individual muscles nor between sexes. The cortisol secretion during a 24-h sampling period 1 week prior to slaughter showed no sex difference. GR concentrations in neck muscle of female calves of four different German cattle breeds (Holstein Friesian, Brown Swiss, Simmental and German Gelbvieh) were rather similar; however, when Brown Swiss with the highest GR levels were compared to Holstein Friesian calves with the lowest concentrations, a significant difference was evident (P < 0.05).