Glycoprotein synthesis and migration in beta cells of the islets of Langerhans as shown by quantitative light- and electron-microscopic radioautography

1982 ◽  
Vol 223 (1) ◽  
Author(s):  
IaraL.G. Brasileiro ◽  
Antonio Haddad ◽  
Georges Pelletier
Keyword(s):  
Beta Cells ◽  
Islets Of Langerhans ◽  
Electron Microscopic ◽  
Glycoprotein Synthesis ◽  
And Migration ◽  
Electron Microscopic Radioautography

scholarly journals Appendix: Radioautographic localization of labelled proteins after incubation of guinea-pig islets of Langerhans with [3H]tryptophan

1974 ◽  
Vol 140 (1) ◽  
pp. 22-23 ◽  
Author(s):  
S. L. Howell ◽  
C. Hellerström ◽  
M. Whitfield
Keyword(s):  
B Cells ◽  
Guinea Pig ◽  
B Cell ◽  
Islets Of Langerhans ◽  
Electron Microscopic ◽  
Storage Granules ◽  
Silver Grains ◽  
Electron Microscopic Radioautography ◽  
Significant Concentration

An analysis was made by electron-microscopic radioautography of the distribution of silver grains over storage granules of A2 and B cells after incubation of isolated guinea-pig islets of Langerhans for 17h in the presence of [3H]tryptophan. A significant concentration of labelled proteins was present in the A2 cell, but not in the B-cell granules.

scholarly journals ELECTRON MICROSCOPIC RADIOAUTOGRAPHIC DETECTION OF SITES OF PROTEIN SYNTHESIS AND MIGRATION IN LIVER

1969 ◽  
Vol 43 (2) ◽  
pp. 237-249 ◽  
Author(s):  
Charles A. Ashley ◽  
Theodore Peters
Keyword(s):  
Endoplasmic Reticulum ◽  
Protein Synthesis ◽  
Rough Endoplasmic Reticulum ◽  
Plasma Proteins ◽  
Liver Slice ◽  
Cell Periphery ◽  
Electron Microscopic ◽  
Golgi Bodies ◽  
And Migration ◽  
Electron Microscopic Radioautography

The sites of synthesis of proteins and their subsequent migration in rat liver have been studied during a 75 min period after labeling of liver-slice proteins by exposure to leucine-H3 for 2 min. Incorporation of the label into protein began after 1 min and was maximal by 4 min. Electron microscopic radioautography showed that synthesis of proteins in hepatocytes occurs mainly on ribosomes, particularly those in rough endoplasmic reticulum and, to some extent, in nuclei and mitochondria. Most of the newly formed proteins leave the endoplasmic reticulum in the course of 40 min, and concurrently labeled proteins appear in Golgi bodies, smooth membranes, microbodies, and lysosomes. A likely pathway for the secretion of some or all plasma proteins is from typical rough endoplasmic reticulum to a zone of reticulum which is partially coated with ribosomes, to the Golgi apparatus, and thence to the cell periphery. The formation of protein by reticuloendothelial cells was measured and found to be about 5% of the total protein formed by the liver.

A simplified method of emulsion coating and development for quantitative electron microscopic radioautography

1978 ◽  
Vol 36 (2) ◽  
pp. 64-65
Author(s):  
K. Yoshida ◽  
F. Murata ◽  
S. Ohno ◽  
T. Nagata
Keyword(s):  
Mass Production ◽  
Identical Condition ◽  
Microscopic Level ◽  
Electron Microscopic Level ◽  
Electron Microscopic ◽  
Simplified Method ◽  
Complicated Process ◽  
Critical Problems ◽  
Electron Microscopic Radioautography ◽  
Quantitative Radioautography

IntroductionSeveral methods of mounting emulsion for radioautography at the electron microscopic level have been reported. From the viewpoint of quantitative radioautography, however, there are many critical problems in the procedure to produce radioautographs. For example, it is necessary to apply and develop emulsions in several experimental groups under an identical condition. Moreover, it is necessary to treat a lot of grids at the same time in the dark room for statistical analysis. Since the complicated process and technical difficulties in these procedures are inadequate to conduct a quantitative analysis of many radioautographs at once, many factors may bring about unexpected results. In order to improve these complicated procedures, a simplified dropping method for mass production of radioautographs under an identical condition was previously reported. However, this procedure was not completely satisfactory from the viewpoint of emulsion homogeneity. This paper reports another improved procedure employing wire loops.

Platelet Incorporation of Labelled Adenosine and Adenosine Diphosphate

1969 ◽  
Vol 22 (02) ◽  
pp. 304-315 ◽  
Author(s):  
E. W Salzman ◽  
T. P Ashford ◽  
D. A Chambers ◽  
Lena L. Neri
Keyword(s):  
Platelet Rich Plasma ◽  
Adenosine Diphosphate ◽  
Platelet Inhibition ◽  
Electron Microscopic ◽  
Platelet Binding ◽  
Minor Degree ◽  
A Minor ◽  
Plasma Marker ◽  
Electron Microscopic Radioautography ◽  
Simultaneous Assessment

SummaryAfter incubation of platelet-rich plasma with labelled adenosine or ADP, platelet incorporation of radioactivity was assessed. Platelets were rapidly separated for counting by filtration through cellulose acetate Millipore. Inulin-H3 served as a plasma marker, and triple isotope techniques permitted simultaneous assessment of the behavior of the adenine and phosphate moieties of ADP without washing of platelets. In other experiments, electron microscopic radioautography was employed to trace the label after platelet incorporation.The results were consistent with previous reports that ADP is dephosphorylated in plasma and is incorporated by platelets only as a dephosphorylated residue, probably adenosine. The label crossed the platelet membrane and entered the platelet, where it was distributed in platelet granules and the agranular cell sap. Concentration within granules occurred to a minor degree.The results support the hypothesis that platelet aggregation by ADP occurs without a persistent bond of ADP to the platelet. Inhibition of aggregation by adenosine probably depends on a metabolic or transport process rather than on competition between adenosine and ADP for platelet binding sites.

Structural and functional considerations of GABA in islets of Langerhans. Beta-cells and nerves

Diabetes ◽  
1991 ◽  
Vol 40 (11) ◽  
pp. 1365-1374 ◽  
Author(s):  
R. L. Sorenson ◽  
D. G. Garry ◽  
T. C. Brelje
Keyword(s):  
Beta Cells ◽  
Islets Of Langerhans

scholarly journals Electron Microscopic Radioautographic Study on Protein Synthesis in Mitochondria of Binucleate Hepatocytes of Aging Mice

2007 ◽  
Vol 7 ◽  
pp. 1008-1023 ◽  
Author(s):  
Tetsuji Nagata
Keyword(s):  
Protein Synthesis ◽  
Labeling Index ◽  
Electron Microscopic ◽  
Protein Precursor ◽  
Binucleate Cells ◽  
Mouse Hepatocytes ◽  
Electron Microscopic Radioautography ◽  
Liver Tissues

In order to study the aging changes of intramitochondrial protein synthesis in mouse hepatocytes, 10 groups of aging mice, each consisting of three individuals, total 30, from fetal day 19 to postnatal year 2, were injected with3H-leucine, a protein precursor, sacrificed 1 h later, and the liver tissues processed for electron microscopic radioautography. On electron microscopic radioautograms obtained from each animal, the numbers of mitochondria, the numbers of labeled mitochondria, and the mitochondrial labeling index labeled with3H-leucine that showed protein synthesis in each hepatocyte, both mononucleate and binucleate cells, were counted and the averages in respective aging groups were compared. From the results, it was demonstrated that the numbers of mitochondria, the numbers of labeled mitochondria, and the labeling indices of intramitochondrial protein syntheses in both mononucleate and binucleate hepatocytes of mice at various ages increased due to development of animals. The numbers of mitochondria, the numbers of labeled mitochondria, and the labeling indices of intramitochondrial protein synthesis in binucleate hepatocytes were more than those of mononucleate hepatocytes at the same aging stages.

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