Search PubMed⌕ Search

Biomedical subjects

T Soji

Publications and source records attributed to T Soji.

At least 55 records · Page 3Linked to original sources
PubMed1989

Granulated 'marginal cell layer' in the rat anterior pituitary gland.

A granulated 'marginal layer cell' was observed in the lining of Rathke's residual pouch of 5 and 10 day-old rat anterior pituitary glands. Immunohistochemistry was not employed to identify the precise function of these cells. However, the cytological characteristics of nearly all of the cells indicated that they resembled GH-secreting cells, with a few displaying morphological features of corticotrophs. In pituitary glands of 5-20 day-old rats, both ends of Rathke's residual pouch extended into the pars distalis at the site of transitional zone of this lobe and of the pars intermedia. The cells within the 'invading' residual pouch contained numerous microvilli. In the middle portion of the residual pouch, cavities lined by 'marginal layer cells' had numerous microvilli and were adjoined by junctional complexes. In the adult rat pituitary gland, there were no granulated cells in the 'marginal cell layer' and no invasion of the residual pouch into the anterior lobe. From these data the possible source of the follicle and of the folliculo-stellate cells in the anterior pituitary of the rat is proposed.

Animals↗
PubMed1989

[A case of neurilemmomatosis].

A 25-year-old man had multiple subcutaneous nodules on the neck, trunk and extremities. Those nodules first appeared in the right popliteal fossa about 15 years ago and thereafter gradually increased in the number with hearing loss, tinnitus, and vertigo. The tumors had smooth surfaces and were elastic hard without any adhesion to the overlying skin or to subcutaneous tissue. Histological examination revealed, in most parts of the lesion, Antoni type A neurilemmoma and the Antoni type B picture at the periphery. As extracutaneous lesion, there were bilateral cerebello-pontine angle neurilemmomas, and spinal and adrenal tumors. Similar subcutaneous tumors have been recognized in 6 of 17 family members of the previous four generations of his family. According to a statistical analysis of 119 cases, including this one, in the Japanese dermatological field, of 75 cases of solitary neurilemmoma and 44 cases of multiple ones, the latter showed male predominance and lower age of the onset. Many of them had tumors not only in the skin but also in extracutaneous sites.

Adrenal Gland Neoplasms↗
PubMed1982

Histochemical study of the rat anterior pituitary LH-gonadotroph after administration of luteinizing hormone releasing hormone (LH-RH).

The aim of this study was to identify the LH-gonadotroph, aided by histochemical demonstrations of adenylate cyclase and acid phosphatase activities in 60-day-old male rats, after a single 100 micrograms injection of luteinizing hormone-releasing hormone (LH-RH). The results obtained are as follows: 1) Separation of the lysosomes from the large secretion granules in the LH-gonadotroph was accomplished in order to demonstrate acid phosphatase, the marker enzyme of lysosomes. 2) The large granules in the LH-gonadotroph decreased remarkably in number within 5 min after LH-RH injection. 3) A marked and prolonged increase in adenylate cyclase activity was observed on the plasma membrane of the LH-gonadotroph after LH-RH injection; this increase continued up to 30 min. 4) At 60 min after LH-RH injection the small secretion granules began to decrease in number. 5) Losing the large granules due to the LH-RH treatment, the LH-gonadotroph resembled the FSH-gonadotroph. From these observations it appears that the FSH-gonadotroph is an immature or storage state LH-gonadotroph and that it changes from an LH-gonadotroph into an FSH-gonadotroph on the loss of its large secretion granules.

Acid Phosphatase↗
PubMed1981

A rapid method for the separation of rat pancreatic islets from collagenase-digested pancreas using Percoll.

The isolation of pancreatic islets from collagenase-digested Wistar rat pancreas was shown by the sedimentation method at a unit gravity using Percoll solution with a density of 1.041 g/ml. The density of digested exocrine tissues was in the range of 1.013-1.041 g/ml, while that of purely isolated islets was in the narrow range of 1.066-1.075 g/ml. More than a hundred islets were obtained freely from each rat pancreas without any gross contamination of digested exocrine tissues. A significant increase was observed in glucose-stimulated insulin release from islet isolated with Percoll in the same pattern as that without Percoll. In addition to the well preserved morphology and function of pancreatic islets isolated by Percoll, the simplicity of the technique strongly commends the usefullness of this method.

Animals↗
PubMed1978

Cytological changes of the pituitary basophils in rats slowly infused with thyrotropin-releasing hormone (TRH).

Young male rats were slowly infused with synthetic TRH, 1 microgram/hr, for 1, 3, 24, 48 and 72 hr, respectively. In the control rats, the basophils of the pituitaries can be divided, in their cytological properties, into the II- (classical thyrotrophs), II/III-,III, (classical LH-cell), and III/IV-type cell. The typical IV-type cells (classical FSH-cell), however, are scarcely found in the young rats. Following 1-hr infusion of TRH, the II-type cells decrease in number with the advancement of granular release, but morphological changes are not yet concrete on the other types of basophils. The II-type cells are quickly invisible following a 3-hr infusion, while the III- and III/IV-type cells remain without any significant changes. The III- and III/IV-type cells are progressively degranulated after a 24-hr infusion. The diameter of secretory granules is reduced to 100--150 nm. The smallest ones below 50 nm in diameter, are disintegrated to disperse into the ground matrix. After degranutlaion, the III/IV-type cells appear to revert to the polygonal or stellate cells with the identical fine structure with the II-type cells. There is evidence that the thyroidectomy cells may develop from the III/IV-type cells only after a 48-hr infusion. After 72 hr, most basophils are provided with the uniform structure of "reversionary II-type cells". In reference to the high serum TSH concentration and no significant change of pituitary TSH concentration under the same experimental condition (Soji, 1978), the present author conclusively postulates that the degranulation of the III/IV-type cells may mainly reflect the conspicuous elevation of serum TSH concentration. The above morphological results are contradictory a plausible view that TRH acts only upon the thyrotrophs to release TSH. The fact that all the basophils ultimately take an appearance of "reversionary II-type cells" in the gland by the prolonged infusion of TRH may not only suggest the share of responsiveness of all the basophils to TRH, but also support the hypothesis of secretory cycle of the basophils.

Animals↗
PubMed1978

Cytological changes of the pituitary basophils in rats slowly infused with LRH and with LRH and THR in combination.

Young male rats were iv infused with synthetic LRH (L) and with L and TRH (T) in combination for 1, 3, 24, 48 and 72 hrs at each dose of 1 microgram/hr. All the basophils of the controls infused with saline are divided into the continuous cyclic types, i.e., II-, II/III, III-, III/IV- and III/IV/II-types. The II-, III- and III/IV-type cells correspond, in fine structure, with those of the classical thyrotrophs, LH- and FSH-gonadotrophs, respectively. A 1-hr infusion of L does not induce any serious changes in all the basophils. After a 3-hr infusion of L, the II-type cells disperse from the gland, while the III/IV-type cells diminished the number of their small secretory granules, and the lumina of endoplasmic reticulum are closed. After a 24-hr infusion, the irregularly shaped III/IV/II-type cells which may revert from the III/IV- to the II-type cells are accumulated, whose secretory granules are remarkably reduced in diameter (50--100 nm). There is evidence to show the diffusion mechanism of the secretory granules into the ground matrix. After a 48-hr infusion of L, most basophils take an appearance of III/IV/II-type cells; after a 72-hr infusion, all the basophils show the homologous fine structure. Thus, the morphological changes of the basophils following the L infusion resemble intrinsically those following the T infusion (Soji, 1976b). From these results, it is tentatively concluded that L does not act only on the III-type cells analogous to the "LH-cells", but universally upon a series of basophils. The transformations of the III/IV-type cells into the III/IV/II-type ones and those of the II-type ones into the III- or III/IV-type ones due to a slow infusion of L are inhibited to some extent by the infusion of T + L. The granular releases from the III/IV- and II-type cells due to a slow infusion of L are also inhibited to some extent by the infusion of T + L. For this reason, both T and L may act, not synergistically but antogonistically, upon the transformation of a series of basophils and their granular release.

Animals↗
PubMed1977

Relationship between the follicular cells and marginal layer cells of the anterior pituitary.

In the anterior pituitaries of adult rats of both sexes, follicular cells resemble marginal layer cells in fine structure. Numerous occurrences of cilia were electronmicroscopically confirmed on the free surface of both cells. The absence of secretory granules, the poor development of endoplasmic reticula and abundant free ribosomes and polysomes are the other coincidental cytological properties between both cells showing the immaturity. Thus, the two cells seem to be intimately related. The follicular cells may play an important role in the mitotic activity of the gland. Cilia and microvilli on the free surface of follicular cells are not easily changed by some experimental conditions.

Animals↗
PubMed1976

Possible sequential transformation of a series of acidophils in the pituitary autografts in the renal capsule of male rats in association with ACTH cell.

In our electron microscopy, acidiphils 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 somaotrophs packed with the large granules of about 350 mmu 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 150-200 mmu in diameter along the cell 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 100-150 mmu in diameter were also distributed in row in the cytoplasmic peripheral area. Gradual loss of the minute granules below 100 mmu 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 simulataneously. 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.

Adrenocorticotropic Hormone↗