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T Setoguti

Publications and source records attributed to T Setoguti.

At least 37 records · Page 2Linked to original sources
PubMed1981

Electron-microscopic studies on the relationship between the frequency of parathyroid storage granules and serum calcium levels in the rat.

In the rat parathyroid, the mean number of storage granules (NSG) per chief cell has been electron-microscopically studied and correlated with the mean serum calcium level (SCL). In animals given 4% CaCl2 plus vitamin D2 for 3 days. SCL is significantly elevated and NSG is increased. When these animals are injected with 2% EDTA, SCl is lowered to 8 mg/dl, but NSG is not affected; in those injected with 4% EDTA, however, SCL declines to a minimum (5.8 mg/dl) after 30 min, and NSG is also decreased. Control SCL are 8.9 mg/dl. These results indicate that storage granules may not be released until SCL is depressed to a certain level. In rats 3 weeks after castration, the chief cells show hyperplastic changes and SCl is at a low concentration (8.0 mg/dl). NSG, however, remains almost within control limits. Castrated animals injected with 4% EDTA show a hypocalcemia and a decrease in NSG, but NSG gradually recovers over a period of 6 h. These data suggest that storage granules can be produced even under lower calcium concentrations. It is concluded that storage granules may be constantly produced and stored, and are released only as an emergency supply of hormone.

Animals↗
PubMed1981

Electron microscopic studies on localization of phosphatases in the laying hen parathyroid.

Localization of phosphatases in the parathyroid of laying hens was examined by electron microscopy. Activities of both alkaline phosphatase and adenosine triphosphatase were intensive on the apposed plasma membranes between contiguous chief cells, but weak or almost lacking on those facing the interstitial connective tissue, and this finding differed from previous data in mammals. This difference seemed to be associated with the fact that in the parenchymal cells of the hens there was found a narrow, delicate filament-rich zone in the peripheral cytoplasm along the basal lamina. Activities of both thiamine pyrophosphatase and inosine diphosphatase were seen in most of the Golgi cisternae having serpentine tubular profiles, and this indicated that the latter cisterna belong to the Golgi apparatus. Acid phosphatase activities were mainly demonstrated in lysosomal dense bodies, including autophagic vacuoles, as well as in most of the lipofuscin granules, and only occasionally encountered in the Golgi apparatus, including the thick membranous cisternae, in contrast with findings in mammals. The reason for this weak activity in this organelle was discussed in relation to calcium metabolism, secretory products, and lysosomes in the laying hen.

Animals↗
PubMed1980

Ultrastructural localization of phosphatases in the rat parathyroid gland.

Ultrastructural localizations of phosphatases were observed in the rat parathyroid gland. Activities of alkaline phosphatase and adenosine triphosphatase were found on the caveolae or pinocytotic vesicles of the capillary endothelia. In the parenchymal cells, they were demonstrated to be stronger both at the plasma membranes facing the pericapillary space and at their transitional portions to the lateral plasma membranes than at the remaining lateral plasma membranes including microvilli. Activities of thiamine pyrophosphatase and inosine diphosphatase were detected on one or two layers of lamellae at the inner face of the Golgi apparatus, and the localization of the latter enzyme was more restricted than that of the former. Additionally, they were sometimes observed also on the blood capillary wall. Contrasted to these enzymes, acid phosphatase activity was demonstrated on the entire Golgi lamellae besides lysosomes, but not on multivesicular bodies, vacuolar bodies and storage granules.

Acid Anhydride Hydrolases↗
PubMed1979

Specific lamellar structures of agranular endoplasmic reticulum in the senile mouse adrenal cortex.

In the adrenal cortex of old mice, lamellar bodies of various shapes frequently appear in the zona reticularis cells. These structures consist of electron dense plates, about 20 nm in width, closely piled at regular distances of about 25 nm. Each plate displays two sheets of unit membranes enclosing a dense material and with several clear spaces between them. These paired membranes usually terminate in round saccules at both ends, but occasionally continue to the tubules of surrounding agranular endoplasmic reticulum. Saccules in several rows, in combination with a part of the lamellae, may be arranged cirularly in the cytoplasm. From these observations, it is proposed that the lamellar body is composed of a cup-shaped mass of flattened cisternae of the agranular endoplasmic reticulum and each of the cisternae is attenuated and closed except at their marginal sacculations. The concentric or horseshoe-shaped profile of the lamellar body observed in this study is accounted for by different section planes through the cup-shaped structure.

Adrenal Cortex↗
PubMed1977

Electron microscopic studies of the parathyroid gland of senile dogs.

The parathyroid gland of healthy senile dogs aged 8.5 to 15 years was compared with that of mature control dogs by examination with the electron microscope. Preparations fixed by perfusion with glutaraldehyde showed the cytoplasmic matrix of most parenchymal cells to be uniformly dense. None of the cells were of the extremely light type and dark cells were much less frequently noted than in preparations fixed by immersion in glutaraldehyde or osmium tetroxide. Syncytial cells and so-called coloid follicles were more frequent in senile dogs than in control dogs. It was suggested that the content of the latter structures is not colloid but necrotic substance hiving origin from the parenchymal cells and that perhaps the occasional cells containing large, membrane-bound inclusions may be degenerating cells which ultimately produce this necrotic substance. Oxyphil cells and mitochondria-rich cells of another type were found in all senile dogs, but not in the controls. These cells, especially the mitochondria-rich cells, frequently contained bizarre mitochondria that were modified in shape, size and arrangement. The most striking feature of these mitochondria was the concentric arrangement of elongated mitochondria which seemed to consist of densely layered cup-shaped mitochondria. Such mitochondria were noted in all senile dogs aged ten years and over. The significance of mitochondrial ple-morphism in the parathyroid gland of senile dogs was discussed.

Aging↗