Autoradiography with Isotopes Emitting Internal Conversion Electrons and Auger Electrons

Forberg, S.; Odeblad, Erik; Soeremark, R; Ullberg, Sven

doi:10.1080/02841866409134060

Cited by 13 publications

(6 citation statements)

References 17 publications

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“…Radioactive iron, 55Fe, is a relatively new isotope in autoradiographic work, although Forberg et al . (1964) suggested from theoretical considerations that the resolution should be high, and Orlic (1968) showed experimentally, using red cell ghosts, that this was the case .…”

Section: Introductionmentioning

confidence: 99%

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Electron Microscope Autoradiography of Erythroid Cells Using Radioactive Iron

Parry

Blackett

1973

The Journal of Cell Biology

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The "circle analysis" method of Williams (1969) and a new improved method employing hypothetical grains described in the previous paper have been used to analyze the distribution of autoradiographic grains over erythroid bone marrow cells labeled with radioactive iron, 55Fe. The resolution obtainable with this isotope was determined by measuring the distribution of grains about a thin line source. This distribution was also used in calculation of the circle size for the Williams's analysis and the distances of hypothetical grains for the new method. The new method provides estimates for the amount of activity in the regions of condensed and extended nuclear chromatin and for the concentration of isotope at the junction between these two areas. The possible significance of activity in this junctional region is discussed.

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Section: Introductionmentioning

confidence: 99%

“…1) . The Auger electrons have energies of 5-6 keV, and some of 0 .5-0 .6 keV (Forberg et al ., 1964) .…”

Section: Introductionmentioning

confidence: 99%

Electron Microscope Autoradiography of Erythroid Cells Using Radioactive Iron

Parry

Blackett

1973

The Journal of Cell Biology

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“…The carbon-iodine bond is stable and specifically located ortho to the hydroxyl group of tyrosine, although histidine residues are also iodinated to a lesser extent (Morrison, Bayse & Danner, 1970). 125I is suitable for autoradiography at the electron-microscopic level (Kayes, Maunsbach & Ullberg, 1962;Forberg, Odeblad, Soremark & Ullberg, 1964). Cohn (1971, 1972) exploited the lactoperoxidase (LPO), glucose-glucose oxidase (GO) system to iodinate plasma membranes of erythrocytes, platelets and L cells in tissue culture, and reported the technique did not provoke cell damage.…”

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confidence: 99%

Iodination (125I) of the apical plasma membrane of toad bladder epithelium: Electron-microscopic autoradiography and physiological effects

Strum

Edelman

1973

J. Membrain Biol.

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Summary. The apical plasma membrane of toad bladder epithelial cells has been enzymatically iodinated, using lactoperoxidase, H20 z (generated by a glucose-glucose oxidase system) and NaI. The site of labeling was demonstrated by electron-microscopic autoradiography; the silver grains (lzsI) were found exclusively overlying the luminal plasma membranes of the epithelium. The iodination reaction reached completion in less than 5 min. The dependence of the degree of iodination on NaI concentrations (range = 6.3 x 10 .8 to 6.3 x 10 -z M) in the mucosal medium was determined. The results suggest that three classes of sites are iodinated within this concentration range. At concentrations of NaI of 6.3 x 10 -6 M or less, iodination of the apical membrane had no significant effect on either the fine structure of the epithelium or on electrophysiological properties. The baseline short-circuit current (SCC) remained steady and the response to vasopressin was unimpaired. At concentrations of 6.3 x 10 -s M NaI and greater, the baseline SCC was depressed and the response to vasopressin was partially inhibited. The results indicate that 125I may serve as a covalent marker (specific for tyrosine and histidine residues) of the apical plasma membrane of epithelia.The two-barrier series model of Koefoed-Johnsen and Ussing (1958) proposes that transepithelial active Na + transport is determined by ratelimiting steps at the apical and basal-lateral plasma membranes. In this model, the electrochemical gradient provides the driving force for Na § entry across the apical plasma membrane and Na § is extruded across the basallateral surfaces by a Na § pump. Reagents that bind covalently to plasma membranes could serve two functions: (1) as markers in the separation of the apical from the basal-lateral surfaces, and (2) as probes for studying the physiological roles of the separate surfaces in the regulation of active Na § transport.Iodination of the apical plasma membrane of the toad bladder was investigated for several reasons: A convenient and rapid method of iodinating 2 J. Membrane Biol. 14

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“…The resultant C-N-bond is stable and located ortho to the hydroxyl group of tyrosine, though to a lesser extent other amino acids also react with diazonium compounds. 12sI was used as the radiolabel because of its suitability for electronmicroscopic autoradiography [12,17]. Sulfanilic acid was used as the parent compound in that the negative charge retards entry into cells.…”

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Differential covalent labeling of apical and basal-lateral membranes of the epithelium of the toad bladder

1976

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The apical (luminal) plasma membrane of toad bladder epithelial cells has been labeled with (125I) diazo-diiodo sulfanilic acid (125I-DDISA) as demonstrated by electron-microscopic autoradiography. The silver grains (125I) were localized exclusively to the apical surface. At concentrations of DDISA of 10(-3) M or less, binding to the apical membrane had no significant effect on the fine structure of the epithelium. At concentrations of DDISA of 10(-6) M or less, the baseline short-circuit current (SCC), and the response to cyclic 3',5'-adenosine monophosphate (cAMP) plus theophylline were unimpaired. At 10(-5) M, baseline SCC was unchanged and the response to cyclic AMP plus theophylline was enhanced. At concentrations of 10(-4) M and greater baseline SCC was depressed and the response to the nucleotide inhibited. The basal-lateral epithelial plasma membranes were labeled by exposing the serosal side to pyridoxal phosphate and reducing the resultant Schiff base with sodium borotritide (3H-NaBH1). In electron-microscopic autoradiographs, the silver grains (3H) were found over the basal and lateral surfaces of the epithelium. At concentrations of pyridoxal phosphate of 10(-4) M and 3H-NaBH1 of 10(-3) M, there were no significant changes in the fine structure of the epithelium. Addition of pyridoxal phosphate (10(-4) M) and NaBH4 (10(-3) M) to the serosal side decreased the baseline SCC significantly but not the response to vasopressin. Covalent attachment of the 125I and the 3H was indicated by resistance to elution in the preparation of the sections for electron-microscopy and the reagent requirements for binding.

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Autoradiography with Isotopes Emitting Internal Conversion Electrons and Auger Electrons

Cited by 13 publications

References 17 publications

Electron Microscope Autoradiography of Erythroid Cells Using Radioactive Iron

Electron Microscope Autoradiography of Erythroid Cells Using Radioactive Iron

Iodination (125I) of the apical plasma membrane of toad bladder epithelium: Electron-microscopic autoradiography and physiological effects

Differential covalent labeling of apical and basal-lateral membranes of the epithelium of the toad bladder

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