ISSN:
1573-6865
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary Three radioimagers, the μ-imager, the β-imager and the phosphorimager, were tested as alternatives to quantitative autoradiography on film, for receptor imaging and pharmacologicalin situ quantitative analysis. Two iodinated ligands125I-interleukin-1α and125I-gonadotropin releasing hormone agonist, were used for receptor characterization in mouse brain and pituitary sections. Due to the high number of the agonist receptors in rat pituitary gland, this tissue was used to compare measurements obtained from digital autoradiograms with classical γ detector determination. This permits the evaluation of radioimager efficiency and absolute quantification. Radioimagers represent an improvement in terms of time of image acquisition. All the radioimagers are more sensitive than film for the detection of low levels of radioactivity. The spatial resolution provided by the μ-imager compares favourably with that obtained on film autoradiograms while digital autoradiograms from the phosphorimager and β-imager did not show precise definition under our experimental conditions. Superimposition of histological structures from the stained sections with radiolabelled areas in the autoradiograms remains, at this time, the unique advantage of film. In conclusion, radioimagers represent an alternative to autoradiography on film or emulsion forin situ quantitative studies on tissue sections. They combine precise imaging forin situ binding studies with easy and direct access to counts in cpm. The improvement in radioimaging technology has, therefore, broughtin situ analysis of iodinated ligand binding to the level of accuracy that is obtained with classical detectors of radioactivity.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02272153
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