An Ultrastructural Autoradiographic Study of the Incorporation of [35S]Cystine in the Wool Fibre Cortex

1973 ◽  
Vol 13 (3) ◽  
pp. 811-819
Author(s):  
R. E. CHAPMAN ◽  
R. T. GEMMELL
Keyword(s):  
Unit Area ◽  
Autoradiographic Study ◽  
Wool Fibre ◽  
Cross Sectional ◽  
Electron Microscope Autoradiography ◽  
Merino Sheep ◽  
Microscope Autoradiography ◽  
Cystine Content ◽  
Chemical Studies ◽  
Filament Bundle

Previous autoradiographic and chemical studies gave incompatible results as regards the incorporation of cystine into and cystine content of the 2 cortical segments of the wool fibre. In this study the incorporation of [35S]cystine into the wool fibre cortex was therefore re-examined by electron-microscope autoradiography. Skin samples were taken from a Merino sheep 1 h and 5 h after intradermal injections of L-[35S]cystine. At both times there was very little incorporation of 35S in the follicle bulbs. By 5 h incorporation occurred distally from the suprabulbar region throughout the zone of macrofibril (filament bundle) formation. More 35S was incorporated per unit area in the paracortex than in the orthocortex, and at the level of maximal uptake near the middle of this zone there was about a 2-fold difference per unit area. However, when the relative cross-sectional areas of the cortical segments were also considered, the actual amount of 35S incorporated at this level was slightly greater in the orthocortex than in the paracortex. These differences in the incorporation of [35S]cystine by the cortical segments agreed with previous results from chemical studies on cortical fractions separated from wool.

Autoradiographic Evidence For The In Situ Synthesis Of Chloroplast And Mitochondrial Rna

1968 ◽  
Vol 3 (3) ◽  
pp. 327-340
Author(s):  
SARAH P. GIBBS
Keyword(s):  
Chloroplast Development ◽  
Unit Area ◽  
Mitochondrial Rna ◽  
Cell Component ◽  
Electron Microscope Autoradiography ◽  
Mitochondrial Ribosomes ◽  
Ochromonas Danica ◽  
Microscope Autoradiography ◽  
Cytoplasmic Ribosomes

The rate of appearance of labelled RNA in the chloroplast and mitochondria as compared with the rate in the remaining cytoplasm was studied in the unicellular flagellate, Ochromonas danica, by electron-microscope autoradiography. Greening cells were labelled with uridine-5,6[3H] for a short (30 min) and a long (2 h) interval and the concentration of label, expressed as grains/unit area, determined for each cell component. The data demonstrate that there is the expected lag in the labelling of the cytoplasm proper, but no apparent lag in the labelling of the chloroplast and mitochondria. This observation, combined with the fact that after the short labelling time the chloroplast and mitochondria have a much heavier concentration of labelled RNA than the surrounding cytoplasm, indicates that most, if not all, chloroplast and mitochondrial RNA is synthesized in situ. The three kinds of ribosomes present in the cell are distinctly different in size. The mitochondrial ribosomes measure 150-170 Å in diameter, the chloroplast ribosomes average 170-200 Å in diameter, whereas the cytoplasmic ribosomes are 210-230 Å in diameter in glutaraldehyde-osmium-fixed cells. During chloroplast development in the light, the number of chloroplast ribosomes increases approximately tenfold.

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.

The Measurement of Fluorophosphate-Reactive Esterase Sites in the Liver of Barbiturate Treated Rats Using Quantitative E.M. Autoradiography

1976 ◽  
Vol 34 ◽  
pp. 102-103
Author(s):  
G. C. Budd
Keyword(s):  
Endoplasmic Reticulum ◽  
Electron Microscope ◽  
Untreated Control ◽  
Unit Area ◽  
Smooth Endoplasmic Reticulum ◽  
Electron Microscope Autoradiography ◽  
Microscope Autoradiography ◽  
Sodium Phenobarbital ◽  
And Control

Male 100 gm Holtzman rats each received 100 mg/Kg of sodium phenobarbital intraperitoneally per day for 4 days. On the fourth day samples of fresh and glutaraldehyde fixed liver were reacted with 10-4 molar tritium labeled diisopropylfluorophosphate (3H-DFP) to permit the measurement of fluorophosphatereactive (FPR) esterase sites using quantitative electron microscope autoradiography (EMARG). The distribution and measured concentrations of FPR sites in the liver of barbiturate treated rats were compared with similar measurements obtained with untreated control rats. Measurements of the density of developed autoradiographic grains (grains/unit area) revealed that in both the treated and control preparations, the FPR sites were concentrated in the rough and smooth endoplasmic reticulum and associated ground cytoplasm of the hepatocytes (RER and SER respectively).

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.

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

Studies in fleece-rot of sheep.

1953 ◽  
Vol 4 (4) ◽  
pp. 430 ◽  
Author(s):  
RH Hayman
Keyword(s):  
Microscopic Examination ◽  
Similar Condition ◽  
Unit Area ◽  
Skin Surface ◽  
Climatic Conditions ◽  
Field Station ◽  
Merino Sheep ◽  
Naturally Occurring ◽  
Sufficient Intensity ◽  
Experimentally Induced

Occasions of unduly heavy and prolonged rainfall during the period April 1946 – July 1951 resulted in the occurrence of fleece-rot in sheep of the Field Station flock in each of the six years. Data obtained from periodic examinations of the flock have been related to the nature of climatic conditions associated with outbreaks of the disease. They show that when rain occurs in falls of sufficient intensity and frequency to wet sheep to the skin for a period of a week or more, fleece-rot may be expected to develop in some of them. The longer the period for which the sheep are kept wet, the greater the number in a flock which will be affected. Fleece-rot was experimentally induced in four out of five Merino sheep known to be susceptible to the condition, whereas five animals known to be resistant were unaffected by the same treatment. Microscopic examination of skin sections taken from naturally occurring cases revealed the presence of a dermatitis. A similar condition was observed in skin sections from the animals in which fleece-rot was experimentally induced. Young sheep were found to be more susceptible than old. There was no association between degree of wrinkling and susceptibility or between 'grip' and susceptibility. When subjectively-appraised attributes of the fleece were related to the occurrence of fleece-rot, confusing results were obtained. However, when measured fleece data, obtained from a group of Merino sheep which had been under observation for four consecutive years, were considered, it was found that those for clean-scoured yield, wax and suint ratio, and density of fibre population per unit area of skin surface, were related to resistance or susceptibility. Nevertheless, a number of animals were found which were susceptible or resistant to the disease despite the nature of their fleece attributes. Differences in susceptibility were found between families of Merino sheep. These are associated with between-family differences for the fleece attributes found to be important in fleece-rot reaction.

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