Abstract
The ultrastructures of cells of the anterior lobe in normal and castrated male rats, 50, 128 and 300 days after the removals were investigated.
1. Chromophobe cell is a maternal or immature cell from which acidophil and basophil may develop. The transformation axis from chromophobe cell to basophils was exclusively stimulated in degree by the castration. Following the castration, granulation was progressive in the enlarged cytoplasm of chromophobe cells, which may turn into polygonal or round basophils.
2. The size-difference in dense beta-granules in basophils is not indispensable for the identification of gonadotroph and thyrotroph, because beta-granules, 100 to 150mμ in diameter, in immature basophil (thyrotroph-type) of castrated rats may grow up to large one, 200 to 250mμ in diameter, which are common with those in chronic castration cells. Thus the castration made the number and the size of granules in basophils increase. Polygonal thyrotroph may correspond to a cell preceding to round gonadotroph in a series of life history of the basophile cell.
3. Beta-and alpha-granules may be produced together in Golgi area. Evidences were presented that vesicles were gradually transformed into granules of variable density. The former, therefore, assumed to be a precursor of the latter. The present observation indicated that granules were stable vehicles for the longterm preservation in the cytoplasm, and vesicles were seemingly important carriages which might work as the active principle.
4. Following the chronic castration, most of basophils turned into the cast ration cells which were thereafter converted into signet-ring cells, in which huge colloid lumen seems to be originated from the coalescence of smooth endoplasmic reticulums. Within 128 and 300 days, signet-ring cells were provided with a degenerating sign on account of prolonged preservation. Big granules (700 mμ) yielded numerously.
5. In addition to alpha-granules, so-called prolactin granules with ellipsoid contour are rarely released out of cell-body by adhesion of the limiting membrane of the granules to the plasma membrane even in male rats. They may not be pushed out but mostly dissolved by enzymatic activity. On the other hand, the discharge of beta-granules presumably takes place in normal and castrated rats by diffusion of the granular content due to the vanishment of the limiting membrane. Diffused material might be eliminated through the membrane of endoplasmic reticulum and stored in it.
6. The above ultrastructures would reinforce the previous doubt of the authors about the subdivision of gonadotroph and thyrotroph.
