Adrenal glands from three aged cows (Japanese Native Cattle)were studied histologically. Animals were 28,21 and 17 years old, respectively.
A remarkable reduction in nuclei density of the outer z. fasciculata as well as the inner z. fasciculata was noted. The data presented here showed highly significant differences between the young and aged cows.
The z. glomerul o sa was most severely affected among the cortical zones in respect to the advancing age. Those enumerated in the z. glomerulosa are, lipid deposition and pigment cells in both the stromal and the parenchymatous tissue. The pigment granules of parenchymatous cells seem to probably be the degenerative material of cell nuclei.
A regional disappearance of the z. glomerulosa was considered as one of the striking change. An appearance of a dense fibrous layer between the z. glomerulosa and the z. fasciculata was discussed from the viewpoint of the downgrowth of cortical cells. Those changes described here would probably imply a reduction in activity of this zone.
The fasciculata cells were much reduced not only in number but also in size. Lipid deposition and dilated sinusoids were also remarkable. Those changes enumerated in the z. fasciculata would probably imply a reduction in activity of this -zone. Fibrotic or hyalinized areas were frequently found within the z. fasciculata.
An extensive appearance of granular cells in the outerz. fasciculata was one of the most striking changes. Characteristics of the cytoplasmic granules were quite similar as those in glomerulosa cells as far as methods used and the functional significance of these granular cells was discussed.