1976 Volume 23 Issue 1 Pages 23-35
In our electron microscopy, acidophils in the pituitary autografts placed in the renal capsules of immature male rats underwent a sequential transformation with the lapse of time: Within 3 and 6 days, all the somatotrophs packed with the large granules of about 350mμ diameter dispersed. The size and number of the granules in somatotrophs were quickly and markedly reduced with severe modification of cell shape. There was evidence during this time course that Siperstein's or Moriarty's corticotrophs might be synonymous with the stellate shape of acidophils with the arrangement of small granules 150-200mμ in diameter along the cell membrane. In other word, they may belong to a step of degranulation process of acidophils. The “acidophils of the small granule type” possibly related to ACTH production according to Yoshimura et al.(1974) were frequently detected in the grafts as elongated or irregularly shaped cells. Their minute granules 100-150mμ in diameter were also distributed in row in the cytoplasmic peripheral area. Gradual loss of the minute granules below 100mμ in diameter eventually made the acidophils to transform into agranular cells. Our own idea that ACTH secretion might correlate with a series of cells transforming along the acidophil-axis was indirectly supported by the present observation on pituitary grafts. On the other hand, basophils rapidly degenerated and died away. Ten and 20 days after autografting, the graft cells which might be principally composed of the cells of acidophil origin enormously proliferated through mitotic division, showing the homologous fine structure, without the normal cell individuality. They always contained three different size and shape of granules simultaneously. Significance of such a rapid and strong response of acidophils to the ectopic replacement in the immature male rats was discussed from the view-point of hypothalamic regulation to simple protein hormones.
