1960 Volume 19 Issue 3 Pages 455-472
Adult female rats of WISTAR strain were ovarioectomized with or without the administration of estron, 8 gamma/day for 10 and 45 days, and of progesterone, 2mg/day for 10 days, from the 5th day after the castration. These animals were decapitated to obtain the pituitary glands for the histological exmination of the changes occurred. The materials were fixed in LEVI's solution and the paraffin sections stained with periodic acid-SCHIFF's reaction (PAS) with the counterstain of HEIDENHAIN's iron-hematoxylin, some of which were also stained with GOMORI's aldehyde fuchsin counterstained by azan (used light green, instead of anilin blue). The present results were as follows:
The beta-cell is the most mobilizing element in the adenohypophysis throughout a series of experiment. At the 10th day after the castration the beta-cells increased in number and became hypertrophic with the enlarged spherical cytoplasm, many of which showed the weak affinity to PAS and were subject to contain the expanded signet-rings. At the 45th day the spherical beta-cells more frequently took places and became larger in size, containing the more expansive seignet-ring, therefore they may analogous in structure to so-called castration cell by MAXIMOW. At the 360th day the cell-bodies of the extraordinarily enlarged castration cells were occupied by the huge colloidal substance homogenously stained with PAS. This characteristic figure reminds us of the follicle of the thyroid gland. While the thyrotrophs which are polygonal or of irregular shape, stained deeply in general with PAS, precisely decreased in number at the 45th and 360th day, in spite of no detectable changes in the cell structure and distribution at the 10th day. In the anterior lobe of castrated rats the alpha-cells were reduced in number and tended to fall into a degeneration, led to the serious impairment or damage in advancing days after the ablation. At the same time the gamma-cells also diminished in number and a few typical chromophobe gamma-cells were scattered somewhere on a probable reason that they became to be transformed into the another kind of cell, alpha- and beta-cells.
In the event of the administration of estrogen, the changes induced by the castration (10th day) were recovered to be in the estrous stage of the normal sexual cycle of pituitary, since the proliferation and hypertrophy of gonadotroph is arrested to develop. Following the injections for 45 days these cells were perfectly shrunk, so that it is impossible for us to distinguish them from the beta-cells themselves; when the overdosage of estrogen was repeatedly injected for many days, all cellular components of pituitary showed thus the obsecure pattern because of the exaggerated degeneration.
When progesterone is given to the castrated rats for 10 days, the frequent occurence of gonadotroph was not swept off and the morphological changes in them showing the acceleration in cell function were not so much progressive as by the estrogen administration.
Present cytological observation offered us an information that two kinds of beta-cells, thyrotroph and gonadotroph, are able to be identified by their shape and internal structure, but incapable to be classified by the localization in the adenohypopysis. Consequently we could not consider that the thyrotroph secretes TSH and the gonadotroph does GTH, because the thyroid gland fails to provide the pattern of disfunction, for example, the reduction in size of follicles and the flattening of the follicular epithelium indicating a loss of TSH content, notwithstanding that there are no beta-cells but a majority of enlarged gonadotrophs occupying the whole area of the adenohypophysis with the subsequent remarkable reduction or vanishment of thyrotrophs. This would lead us to a consideration that two kinds of beta-cells do not link with the independent cell forms, but may involve in the different functional states in the same cell.
