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Volume 40, Issue 5
Displaying 1-8 of 8 articles from this issue
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Hideo ISONO, Katsuko MIYAKE, Shizuko SHOUMURA, Russell J. BARRNETT1977 Volume 40 Issue 5 Pages 367-380
Published: 1977
Released on J-STAGE: February 20, 2009
JOURNAL FREE ACCESSThe parathyroid glands of mice from neonatal to 18 months old were studied by electron microscopy. Most chief cells of the parathyroid gland of one-day-old mice contained a small number of cell organelles and a few secretory granules. In most chief cells of mice between the ages of 3 and 21 days, the cytoplasmic volume of the cell and the number of free ribosomes, mitochondria and secretory granules were increased with age. At 21 days, the Golgi apparatus and the granular endoplasmic reticulum were relatively well developed. Most chief cells of mice between the ages of 1 and 6 months contained numerous free ribosomes, abundant mitochondria, well-developed granular endoplasmic reticulum and Golgi apparatus, and many secretory granules. Relatively numerous secretory granules were observed near the plasma membrane. In most chief cells of mice between the ages of 8 and 18 months, free ribosomes, prosecretory granules and secretory granules were reduced in number with age. An increase of the tortuosity of plasma membranes was observed with each stage of development. The results are discussed in relation to the function of the parathyroid gland during postnatal development.View full abstractDownload PDF (28583K) -
Kikuko IMAMOTO, Nobuo SHIMIZU1977 Volume 40 Issue 5 Pages 381-389
Published: 1977
Released on J-STAGE: February 20, 2009
JOURNAL FREE ACCESSFollowing unilateral destruction of the substantia nigra of the rat, terminal degenerations in the neostriatum were examined under an electron microscope. The early changes that appeared at 15hrs after destruction were characterized by the increased electron density of the terminals and an accumulation of glycogen particles in the astrocytal processes surrounding such terminals and in the perivascular areas. The postsynaptic sides of the early degenerating terminals were often presumed to be dendritic spines with a fluffy material and the spine apparatus. Some were small dendrites with neurotubules.
The degenerating terminals gradually increased the electron density, and irregularly shaped dense bodies appeared in these terminals. At 2 and 3 days after destruction, degenerating terminals became shrunken into dense bodies of 0.5-0.7μ in diameter. They were completely enclosed by the astrocytal swollen processes with glycogen particles, and then digested by these glial processes. At 7 days after destruction, there was no dense degenerating terminal, whereas the degeneration of myelinated axons remained till 2 weeks, showing dense axoplasm and disintegrated lamellar structures of the myelin sheaths. These results indicate that the terminal degeneration of the dopamine neuron in the neostriatum appears within a few days and disappears after 7 days, corresponding well to those results obtained by the Fink-Heimer method.View full abstractDownload PDF (17114K) -
Yosaburo SHIBATA1977 Volume 40 Issue 5 Pages 391-406
Published: 1977
Released on J-STAGE: February 20, 2009
JOURNAL FREE ACCESSThe ultrastructure of ventricular cardiac muscles from representatives of all the vertebrate phyla is examined with the electron microscope using thin sections and freeze-fracture replicas. Contrary to the mammalian heart in which the width of the muscle fiber is usually over 10μm, and T-tubules and sarcoplasmic reticulum (SR) are well developed, non-mammalian cardiac muscles in general show small fiber diameter of less than 5μm, lack T-tubules, and reveal a wide variety in the degree of SR development. The rainbow trout and the lamprey, as well as the sparrow, reveal well-developed SR and numerous subsurface cisternae (SC) in proximity to Z line level. On the other hand, lizard and frog ventricles show poor development of SR and infrequent SC at A band level.
Nexus (gap junction) can be identified in all the vertebrate hearts examined by freeze-fracture technique. However, it is much smaller and more sparsely distributed in non-mammalian hearts than in mammals.
These morphological differences may imply different electrophysiological properties correlated with the small fiber diameter of the lower vertebrate cardiac muscles.View full abstractDownload PDF (26756K) -
Kazuhiro ABE, Takashi ITO1977 Volume 40 Issue 5 Pages 407-420
Published: 1977
Released on J-STAGE: February 20, 2009
JOURNAL FREE ACCESSPeyer's patches of adult mice were morphologically studied by light microscopy.
The patch is topographically divided into four portions: germinal center, follicular area, parafollicular area and dome area. The germinal center consists of light and dark zones. The follicular area surrounds the germinal center, especially the light zone which has an apical pole directed toward the mucosal surface. The parafollicular area surrounds the follicular area and contains postcapillary venules with high endothelium. The dome area is situated just above the follicular area. The epithelium over the dome area is infiltrated with numerous lymphocytes.
Quantitatively, the germinal center, follicular area and parafollicular area are almost similar in volume (about 30%) and the dome area constitutes only a small portion (about 10%). The density of small lymphocytes is highest in the follicular area and lowest in the germinal center. Out of the total small lymphocytes in the patch, 8.4% are included in the germinal center; 58.2% in the follicular area; 26.7% in the parafollicular area; and 3.8% in the dome area. Intraepithelial small lymphocytes are almost twice as abundant in the dome as in the villi. In the dome, almost half the intraepithelial lymphocytes are above the nuclear level of the epithelial cells, whereas in the villi 7.3% of intraepithelial lymphocytes are above the nuclear level.
The results suggest that the functional structure of the Peyer's path is similar to that of peripheral lymphatic tissues.View full abstractDownload PDF (16335K) -
Masahiro MURAKAMI, Tatsuo SHIMADA, Tomihide NISHIDA, Morio SAKIMA1977 Volume 40 Issue 5 Pages 421-429
Published: 1977
Released on J-STAGE: February 20, 2009
JOURNAL FREE ACCESSThe mammary glands of rats during and after lactation were examined by scanning electron microscopy.
In the lactating mammary gland the luminal surface of the secretory epithelial cells were covered with microvilli, relatively sparse and short, and characterized by the presence of two distinct types of secretory materials: large lipid droplets with varying grades of protrusion and small protein granules randomly distributed. Fracture of the secretory epithelial cells revealed both the the presence of a connection of the protruding lipid droplet to the apical cytoplasm by a thin bridge, and openings of holes containing protein granules into the alveolar lumen.
After weaning, the mammary alveoli underwent gradual and progressive involution. Three to seven days later, the luminal surface of the secretory epithelial cells became irregularly undulated and almost completely lost either their protruding lipid droplets or protein granules. Occasionally, necrotic secretory epithelial cells with exploded cytoplasm were detached from the adjacent cells. By the 10th day, involution of the mammary gland was further advanced. A marked collapse of the alveoli was noticed associated with focal luminal obliteration.View full abstractDownload PDF (16248K) -
Katsuko KATAOKA, Keisuke SHIMIZU, Junzo OCHI1977 Volume 40 Issue 5 Pages 431-433
Published: 1977
Released on J-STAGE: February 20, 2009
JOURNAL FREE ACCESSFormaldehyde-induced fluorescence histochemistry demonstrates three kinds of monoamine-containing cells in the normal finch pancreas. Most islet cells have weak fluorescence of intermediate color between yellow and green, suggesting the storage of both catecholamine and indolamine. These cells take up precursors of amines and related compounds. A small number of cells have intense blue-green fluorescence of catecholamine, but the type of the cells is unknown. Very few cells have intense yellow fluorescence, and at least some of them are 5-hydroxytryptamine-containing enterochromaffin cells.View full abstractDownload PDF (1988K) -
L. C. U. JUNQUEIRA, F. REINACH, L. M. M. SALLES1977 Volume 40 Issue 5 Pages 435-443
Published: 1977
Released on J-STAGE: February 20, 2009
JOURNAL FREE ACCESSElectron microscope study of the melanophores in three species of teleosts shows the presence of 11nm filaments in their cytoplasm. Three sympathomimetic substances (adrenalin, 6-hydroxydopamine and 5-hydroxydopamine) act in vivo and in vitro to induce a considerable increase in the number of these filaments, mainly in the cell branches.View full abstractDownload PDF (13987K) -
1977 Volume 40 Issue 5 Pages 445-448
Published: 1977
Released on J-STAGE: February 20, 2009
JOURNAL FREE ACCESSDownload PDF (397K)
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