scholarly journals AN ELECTRON MICROSCOPE AUTORADIOGRAPHIC STUDY OF THE NEURONAL AND EXTRANEURONAL LOCALIZATION OF LABELED AMINE IN THE HEART OF THE BAT AFTER ADMINISTRATION OF TRITIATED NOREPINEPHRINE

1974 ◽  
Vol 62 (3) ◽  
pp. 610-624 ◽  
Author(s):  
Michael D. Gershon ◽  
Martin Hagopian ◽  
Eladio A. Nunez
Keyword(s):  
Electron Microscope ◽  
Specific Activity ◽  
Ventricular Myocardium ◽  
Autoradiographic Study ◽  
Thin Filaments ◽  
Electron Microscope Autoradiography ◽  
Morphological Criteria ◽  
Neural Processes ◽  
Microscope Autoradiography ◽  
Nonrandom Distribution

The localization of labeled amine in the heart of the bat after administration of tritiated norepinephrine (NE) was studied by means of electron microscope autoradiography. Monoamine oxidase was inhibited so that the distribution of amine in both neuronal (Uptake1) and extraneuronal (Uptake2) sites could be analyzed. Labeling was nonrandom in both the atrial and ventricular myocardium. The highest relative specific activity was found in neural processes which showed morphological criteria of terminal adrenergic axons. Analysis of the distribution of label around the labeled axonal varicosities indicated that the radioactive amine was more concentrated peripherally than centrally in these structures. Label was also found over cardiocytes in both atrium and ventricle. The pattern of this labeling indicated that the radioactive amine was associated with myofilaments. In the ventricle, I bands were most heavily labeled, indicating a probable association of radioactive amine with thin filaments. Labeling was prevented by administration of phenoxybenzamine and decreased only in cardiocytes by normetanephrine. The nonrandom distribution of labeled amine within cardiocytes supports the view that Uptake2 represents not only a second mechanism of inactivation of the sympathetic neurotransmitter, but may also be involved in the mediation of some of the action of NE on cardiac muscle.

Electron microscope autoradiography of isolated molecules

1978 ◽  
Vol 36 (2) ◽  
pp. 192-193
Author(s):  
M. Bouteille ◽  
E. Delain ◽  
N. Angelier
Keyword(s):  
Electron Microscope ◽  
High Efficiency ◽  
Specific Activity ◽  
Molecular Complexes ◽  
Electron Microscope Autoradiography ◽  
Microscope Autoradiography ◽  
Loop Technique ◽  
Silver Grains ◽  
Isolated Molecules

The LIGOP method of electron microscope autoradiography which consists in a combination of coating Ilford emulsion with the loop technique and developing with gold latensification and phenidon has proved to provide small, compact developed silver grains with high efficiency.This has made it possible to use this technique with very small materials such as isolated molecules of molecular complexes.The method was assayed first with 3H-Thymidine labelled T7 phages DNA molecule with 630,000 cpm/μg specific activity (fig. 1). The molecules were spread using the adsorption technique constrasted by rotatory shadowing with platinum and then subjected to autoradiography. The Labelling was sufficient to obtain quantitative data in which the spread molecules were considered as a material comparable to a “hot line”. The efficiency (45%) and the HD value (1600 Å) were calculated.The method was also applied to transcription units of pleurodeles oocytes nucleoli (fig. 2) labelled in vitro with 3H-Uridine.

scholarly journals Cytological events involved in protein synthesis in cellular and syncytial trophoblast of human placenta. An electron microscope autoradiographic study of [3H]leucine incorporation.

1978 ◽  
Vol 76 (2) ◽  
pp. 400-417 ◽  
Author(s):  
D M Nelson ◽  
A C Enders ◽  
B F King
Keyword(s):  
Protein Synthesis ◽  
Electron Microscope ◽  
Autoradiographic Study ◽  
Leucine Incorporation ◽  
Electron Microscope Autoradiography ◽  
Placental Villi ◽  
Microscope Autoradiography ◽  
Syncytial Trophoblast ◽  
Time Point

Electron microscope autoradiography has been used to study protein synthesis in syncytial and cellular trophoblast of term human placental villi incubated in vitro with tritiated leucine ([3H]leu). Autoradiographs were analyzed using the hypothetical grain analysis of Blackett and Parry (1973. J. Cell Biol. 57:9-15). The results of this study demonstrated that both cellular and syncytial trophoblast have marked capacities for protein synthesis. Cellular trophoblast synthesized protein in both its rough endoplasmic reticulum (RER) and its ground plasm which contained abundant free ribosomes. The vast majority of 3H-proteins remained within the cell, with some of the proteins synthesized ultimately appearing in the nucleus. A small percentage of grains was ultimately associated with the trophoblast basement membrane. In syncytial trophoblast, the RER was the dominant site for protein synthesis. The autoradiographic data suggested that, as in the cellular trophoblast, the vast majority of 3H-proteins synthesized by the syncytial trophoblast remained within the syncytial trophoblast throughout the incubation period. The major portion of [3H]leu-labeling present in the syncytial trophoblast of villi incubated the longest times (4 h+) remained in association with the RER. Labeled proteins did not become concentrated in syncytial trophoblast Golgi apparatus, vesicles, or granules. In contrast to cellular trophoblast, the nuclei in the syncytium did not contain 3H-proteins at any time-point studied.

scholarly journals Uptake and subcellular distribution of [3H]arachidonic acid in murine fibrosarcoma cells measured by electron microscope autoradiography.

1985 ◽  
Vol 101 (2) ◽  
pp. 573-581 ◽  
Author(s):  
E J Neufeld ◽  
P W Majerus ◽  
C M Krueger ◽  
J E Saffitz
Keyword(s):  
Electron Microscope ◽  
Specific Activity ◽  
Cell Types ◽  
Cellular Membrane ◽  
Electron Microscope Autoradiography ◽  
Murine Fibroblasts ◽  
Fibrosarcoma Cells ◽  
Microscope Autoradiography ◽  
Murine Fibrosarcoma ◽  
Short Times

We have used quantitative electron microscope autoradiography to study uptake and distribution of arachidonate in HSDM1C1 murine fibrosarcoma cells and in EPU-1B, a mutant HSDM1C1 line defective in high affinity arachidonate uptake. Cells were labeled with [3H]arachidonate for 15 min, 40 min, 2 h, or 24 h. Label was found almost exclusively in cellular phospholipids; 92-96% of incorporated radioactivity was retained in cells during fixation and tissue processing. All incorporated radioactivity was found to be associated with cellular membranes. Endoplasmic reticulum (ER) contained the bulk of [3H]arachidonate at all time points in both cell types, while mitochondria, which contain a large portion of cellular membrane, were labeled slowly and to substantially lower specific activity. Plasma membrane (PM) also labeled slowly, achieving a specific activity only one-sixth that of ER at 15 min in HSDM1C1 cells (6% of total label) and one-third of ER in EPU-1B (10% of total label). Nuclear membrane (NM) exhibited the highest specific activity of labeling at 15 min in HSDM1C1 cells (twice that of ER) but was not preferentially labeled in the mutant. Over 24 h, PM label intensity increased to that of ER in both cell lines. However, NM activity diminished in HSDM1C1 cells by 24 h to a small fraction of that in ER. In response to agonists, HSDM1C1 cells release labeled arachidonate for eicosanoid synthesis most readily when they have been labeled for short times. Our results therefore suggest that NM and ER, sites of cyclooxygenase in murine fibroblasts, are probably sources for release of [3H]arachidonate, whereas PM and mitochondria are unlikely to be major sources of eicosanoid precursors.

scholarly journals Formation of Cytoplasmic Granules in Human Eosinophilic Myelocytes: An Electron Microscope Autoradiographic Study

Blood ◽  
1968 ◽  
Vol 31 (2) ◽  
pp. 188-194 ◽  
Author(s):  
MARTHA E. FEDORKO
Keyword(s):  
Bone Marrow ◽  
Electron Microscope ◽  
Golgi Complex ◽  
Autoradiographic Study ◽  
Electron Microscope Autoradiography ◽  
Cytoplasmic Granules ◽  
Microscope Autoradiography ◽  
Intracellular Amino Acids ◽  
Flow Through

Abstract The intracellular flow of tritiated lysine in human eosinophilic myelocytes was studied by electron microscope autoradiography so that information could be obtained on the formation of eosinophil granules. Bone marrow particles obtained from a patient with a marked increase in the number of bone marrow eosinophils were incubated in vitro for periods up to 150 minutes. The percentage of cytoplasmic grains over the Golgi complex rose from 11 percent at 5 minutes to 28 percent by 30 minutes and fell to 15 percent at 150 minutes. Grains over cytoplasmic granules steadily rose to 37 percent by 150 minutes. These results are statistically significant and demonstrate that: human eosinophilic myelocytes are able to form cytoplasmic granules under the in vitro conditions employed, and that intracellular amino acids or proteins flow through the Golgi complex before incorporation into granules.

Incorporation of Cholesterol into Peripheral Nerve Myelin

1972 ◽  
Vol 30 ◽  
pp. 334-335
Author(s):  
Frank A. Rawlins
Keyword(s):  
Electron Microscope ◽  
Sciatic Nerve ◽  
Electron Microscope Autoradiography ◽  
Myelin Sheaths ◽  
Microscope Autoradiography ◽  
Grain Distribution ◽  
Sciatic Nerves ◽  
Autoradiographic Analysis ◽  
Old Mice ◽  
Short Times

Several speculations exist as to the site of incorporation of preformed molecules into myelin. The possibility that an autoradiographic analysis of cholesterol-1,2-H3 incorporation at very short times after injection might shed some light in the solution of that problem led to the present experiment.Cholesterol-1,2-H3 was injected intraperitoneally into 24 tenday old mice. The animals were then sacrificed at 10,20,30,40,60,90,120 and 180 min after the injection and the sciatic nerves were processed for electron microscope autoradiography. To analyze the grain distribution in the autoradiograms of cross and longitudinal sections from each sciatic nerve myelin sheaths were subdivided into three compartments named: outer 1/3, middle 1/3 and inner 1/3 compartments.It was found that twenty min. after the injection of cholesterol -1.2-H3 (Figs. 1 and 2), 55% of the total number of grains (t.n.g) found in myelin were within the outer 1/3 compartment, 9% were within the middle 1/3 and 36% within the inner 1/3 compartment

scholarly journals Electron microscope autoradiographic study of intestinal absorption of decanoic and octanoic acids in the rat.

1975 ◽  
Vol 65 (2) ◽  
pp. 383-397 ◽  
Author(s):  
H Carlier ◽  
J Bezard
Keyword(s):  
Fatty Acids ◽  
Electron Microscope ◽  
Intestinal Absorption ◽  
Common Duct ◽  
Autoradiographic Study ◽  
Electron Microscope Autoradiography ◽  
Blood Capillaries ◽  
Medium Chain ◽  
Medium Chain Fatty Acids ◽  
Chain Fatty Acids

Intestinal absorption of [3H]octanoic acid and [3H]decanoic acid was investigated in the rat by electron microscope autoradiography. The common duct (bile and pancreatic common duct) of the rats was diverted and a loop of the duodenum was cannulated 24 h later. The lipid mixture to be investigated was introduced into each experimental loop, and after 15 min or less the loop was removed. One part of each loop was used to determine the distribution of radioactivity in different lipid fractions, and an autoradiographic study was performed on the other part of the loop. Radioactivity distribution studies confirmed that medium chain fatty acids are absorbed in their nonesterified form and established that these fatty acids are absorbed much more rapidly than oleic acid. Autoradiographic studies indicated that the medium chain fatty acids are taken up in a molecular or aggregate molecular form, leave the epithelial cells by way of the lateral plasma membrane, and are next found in the blood capillaries. Our results suggest that the Golgi complex does not play an important role in the absorption of unesterified fatty acids.

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