All issues
Successor
Volume 42 (1979)
- Issue 5 Pages 489-
- Issue 4 Pages 399-
- Issue 3 Pages 197-
- Issue 2 Pages 95-
- Issue 1 Pages 1-
Volume 42, Issue 5
Displaying 1-7 of 7 articles from this issue
- |<
- <
- 1
- >
- >|
-
Hidemaro OKINO, Susumu MATSUI, Seiji SHIODA, Yasumitsu NAKAI, Kazumasa ...1979 Volume 42 Issue 5 Pages 489-505
Published: 1979
Released on J-STAGE: February 20, 2009
JOURNAL FREE ACCESSThe pituitary thyrotrophs and thyroid follicular cells of rats were studied by electron microscopy and morphometric analysis at 5, 10, 20, 30 and 60min after intravenous injection of 200μg of thyrotropin releasing hormone (TRH) and at 10min after injection of 10μg TRH.
Multiple granule extrusions in a group were often observed around the pituitary thyrotrophs at 5, 10 and 20min after administration of 200μg TRH, as well as at 10min after injectiom of 10μg TRH. The number of released granules reached its maximum at 10min after 200μg TRH injection, but the total number of secretory granules in the cytoplasm of thyrotrophs did not show any significant variation throughout the experimental period. Percent area of the rough endoplasmic reticulum indicated the maximum value at 20min and that of the Golgi apparatus at 10min. These findings suggest that TRH stimulates the thyrotroph and accelerates synchronously the secretion as well as the synthesis of TSH.
In the thyroid follicular cells after 200μg TRH injection, numerous small vesicles which might be secretory granules were found in the apical cytoplasm at 5 and 10min. Pseudopod formation on the luminal surface and accumulation of colloid droplets and lysosome-like granules in the apical cytoplasm were most frequently observed at 20 and 30min. The value of the mean ratio of the diameter of the colloid lumen to the cell height of follicular cells in the thyroid follicles of all experimental animals stimulated with TRH decreased much more than that of the control animals. This value may indicate the increased activity of follicular cells to reabsorb the colloid.View full abstractDownload PDF (8625K) -
Sakashi NOMURA, Yoshiki SHIBA, Yojiro MUNEOKA, Yoshinobu KANNO1979 Volume 42 Issue 5 Pages 507-516
Published: 1979
Released on J-STAGE: February 20, 2009
JOURNAL FREE ACCESSPremetamorphic papillae of an anuran tadpole (Rana japonica) were studied by scanning and transmission electron microscopy. Premetamorphic papillae of several shapes are seen in and around the oral cavities of tadpoles during late larval and early metamorphic stages. These papillae are composed of three parts: the apical cellular part, the underlying connective tissue core and the epithelial covering. In the apical cellular part, two populations of cells are observed: apical and basal cells. The apical cell has a slender cytoplasmic process whose apical surface is exposed in the oral cavity. The basal cell is located at the basal portion of the apical cellular part of the papilla without reaching the oral cavity. A long solitary microvillus and a bunch of short microvilli are seen on the apical surface of each apical cell. The apical cells contain dense-cored vesicles of 100nm diameter and make synaptic contacts at their basal membranes with terminals of nerve fibers. Possible chemoreceptive function of the premetamorphic papilla is dicussed.View full abstractDownload PDF (5704K) -
Kazutomo DATE1979 Volume 42 Issue 5 Pages 517-531
Published: 1979
Released on J-STAGE: February 20, 2009
JOURNAL FREE ACCESSSynovial membranes from human and rabbit joints were observed by scanning electron microscopy.
1. The surfaces of synovial membranes present locally variable appearances. In some parts cytoplasmic processes of lining cells extend long and flat causing an appearance like overlapping renal podocytes, whereas in other parts the cells protrude in cauliflower-like or more smooth-surfaced round bodies.
2. In cracked surfaces of synovial membranes, two types of lining cells are distinguished. One is the cell which has more surface processes and numerous granules in the cytoplasm, the other is the cell which has fewer processes and better developed endoplasmic reticulum without granules.
3. Fibroblasts apparently forming collagen fibers are observed in the subsynovial tissue. Two types of fibrogenesis are found. In the first type microfibrils seem to be formed extracellularly, whereas in the second type bundles of filaments are preformed in the cytoplasm and they appear to be extruded directly from the cell surface.View full abstractDownload PDF (10755K) -
Kenichi TAKAYA1979 Volume 42 Issue 5 Pages 533-542
Published: 1979
Released on J-STAGE: February 20, 2009
JOURNAL FREE ACCESSElectron microscopy of unstained, fresh air-dried spreads of the mouse brain revealed well-preserved ultrastructures of neurons and synaptic boutons filled with synaptic vesicles. Energy dispersive X-ray microanalysis of the neuron nucleus disclosed peaks for phosphorus, sulfur, chlorine and potassium. Analysis of large regions (spots of ca. 1μm in diameter) on the neuron nucleus revealed peaks for magnesium, whereas that of regions on the cytoplasm rarely disclosed the element, which was confirmed by removal of the background noise using a micro-Edit computor system. Analysis of regions on synaptic boutons except mitochondria also indicated peaks for magnesium.View full abstractDownload PDF (2617K) -
Kiyotaka TOSHIMORI, Chikayoshi OURA1979 Volume 42 Issue 5 Pages 543-550
Published: 1979
Released on J-STAGE: February 20, 2009
JOURNAL FREE ACCESSAn unusual architecture of occluding junctions between surface cells in teleost ovarian follicles was observed by electron microscopy, by using the freeze-fracture technique. On the P-face, double strands of intramembraneous particles are observed. A narrow furrow-like gap is recognized between two rows of particles in such double strands. On the E-face, two types of grooves can be distinguished. Type I groove consists of a wide furrow. Type II groove, which appears to be sequent to type I groove, consists of a pair of “sub-grooves” running parallel. Further, a row of particles appears to be located in the bottom of type I groove or between two “sub-grooves” of type II groove. These observations suggest that the double strands on the P-face are registered with the grooves (type I or type II) on the complementary E-face and that a row of particles on the E-face is registered with a furrow-like region between two rows in the double strands on the P-face. In other words, a single unit of the juncture of the present occluding junction is thought to consist of triplicated junctional strands.View full abstractDownload PDF (5316K) -
Hitoshi TAKAHASHI, Takashi YAMADORI1979 Volume 42 Issue 5 Pages 551-561
Published: 1979
Released on J-STAGE: February 20, 2009
JOURNAL FREE ACCESSThe early stage of migration of neural crest cells was observed in the midbrain level of bantam embryos (5-somite stage to 15-somite stage) by transmission electron microscopy. It was confirmed that the migration of the neural crest cells starts at the stage of 7-8 somites and ends at the stage of about 14 somites. During this period, not only the contact of migrating crest cells with each other but also the contact between migrating cells and superficial ectodermal cells and/or neural tube cells was observed. Intercellular distance in those contact regions was 3-4nm. The contact between the migrating crest cell and the basement membrane of the neural tube cell and of the ectodermal cell as well as the contact between the neural crest cell and the fibrillar structure in the environment was also seen. These findings suggest the possibility of transitory interaction for migration between neural crest cells with each other, between neural crest cells and cellular components of the environment where these crest cells migrate, and between neural crest cells and extracellular structures in the environment.View full abstractDownload PDF (7936K) -
1979 Volume 42 Issue 5 Pages 563
Published: 1979
Released on J-STAGE: February 20, 2009
JOURNAL FREE ACCESSDownload PDF (138K)
- |<
- <
- 1
- >
- >|