By EM, zona fasciculata cells of group I showed numerous lipid droplets, many mitochondria with vesicular cristae, smooth endoplasmic reticulum, and euchromatic nucleus with peripheral clumps of heterochromatin (Figure 11).
Zona fasciculata cells of group II showed vacuoles of variable sizes with electron-dense cores, mitochondria with destroyed cristae, many lipid droplets without discernible outline, and a shrunken hyperchromatic nucleus with an irregular outline.
(12) The morphology of individual cells may be quite heterogeneous, with varying proportions of 4 different types of cells: clear cells resembling zona fasciculata cells
, cells resembling ZG cells, compact cells indistinguishable from those of the zona reticularis, and a group of cells designated as "hybrid" cells with cytologic features of both zona fasciculata and ZG cells.
Adrenocortical cells cease to divide and are directed into G0 phase and subsequently probably differentiate into zona fasciculata cells. This assumption may be confirmed by our earlier findings demonstrating that at day 5 of adrenal regeneration, expression of Cyp11b1 reached level comparable to control .
Igf1 mRNA levels are very high in the zona fasciculata cells and Igf1 is known to stimulate proliferation and steroidogenesis in human, rat, and bovine adrenocortical cells [39, 43, 44].
Ho, "Further study of aldosterone secretion-inhibitory factor and brain natriuretic peptide on cortisol production of Guinea pig zona fasciculata cells
," Chinese Journal of Physiology, vol.
Unlike the Me[SO.sub.2]-PCBs (polychlorinated biphenyls), which are irreversibly associated with specific PCB-binding proteins in their target cells (e.g., in nonciliated bronchiolar cells), Me[SO.sub.2]-DDE is irreversibly bound in the adrenal zona fasciculata cells
. Me[SO.sub.2]-DDE has subsequently been shown to be a highly potent toxicant that induces mitochondrial degeneration and cellular necrosis following a CYP11B1-catalyzed metabolic activation in the adrenal cortex in mice (11,12).