Stereological study of normal and apoptotic cell populations in the adrenal gland in calves

Morphometrical features of the adrenal gland in calves were assessed using stereological methods for normal and apoptotic cells. Adrenal glands were obtained from calves (n = 16) after they were slaughtered in a commercial abattoir. Quantitative data of nuclear size showed the highest values in the noradrenaline-storing region for all parameters, whereas the nuclei of the zona fasciculata were significantly larger than those of the other cortical regions. Data of nuclear size and shape of apoptotic cells reflected their morphometrical features; as expected, a notable decrease in the nuclear size and a more irregular shape were found in apoptosis with respect to the normal nuclei in all adrenal regions. The volume fraction data supplied the percentage of the adrenal gland occupied by each histological zone, highlighting the zona fasciculata as being the most extensive one. A significant increase in V-v(nucl/tis), Sv(wnucl/tis), and Nv(nucl/tis)was observed in cortical regions with respect to the medullar regions. A comparison between normal and apoptotic nuclei indicated a:highly significant decrease in V-v(nvcl/ tis), Sv(nucl/tis), and Nv(nucl/tis) for the apoptotic nuclei in all the adrenal zones. The apoptotic nuclei figures found in all the adrenal regions suggest that a process of cell renovation occurred in all the zones, although the higher number of apoptosis in zona reticularis is in agreement with previous results that have pointed out this zone as being a cell senescence region. The results of discriminant analyses gave the parameter required and the percentage of correct classifications for discriminating between normal nuclei, between apoptotic nuclei and between normal and apoptotic nuclei. Copyright (C) 2001 S. Karger AG. Basel.