Stereological study of the adrenal gland of calves treated with clenbuterol

Stereological methods were used to investigate the morphometric variations in the adrenal cell population of calves dosed orally with clenbuterol at an anabolic dose of 20 mug/kg bodyweight per day for 12 weeks. In the treated group the size of the nuclei increased with respect to the control group, and the increases were significant for the maximum linear parameters in all the regions except the zona fasciculata. The largest increases were observed in the epinephrine-producing cells. The quantitative stereological data showed highly significant increases in the nuclear volume fraction, the nuclear surface density and the numerical density in the zona fasciculata of the treated group.