Autoradiography and density gradient separation of technetium-99m-exametazime (HMPAO) labelled leucocytes reveals selectivity for eosinophils.

Puncher, M.R.B. and Blower, P.J. (1994) Autoradiography and density gradient separation of technetium-99m-exametazime (HMPAO) labelled leucocytes reveals selectivity for eosinophils. European Journal of Nuclear Medicine, 21 (11). pp. 1175-1182. ISSN 0340-6997. (The full text of this publication is not available from this repository)

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Abstract

Technetium-99m-Exametazime (HMPAO) is widely used for radiolabelling leucocytes for localization of infection. The subcellular distribution of radionuclide in the labelled cells and the distribution of radioactivity among the leucocyte population are incompletely understood. Frozen section autoradiography was used to determine quantitatively the distribution of Tc-99m in leucocytes labelled with Tc-99m-Exametazime. Sections of rapidly frozen suspensions of labelled leucocytes in plasma were autoradiographed on Ilford K2 emulsion and stained with haematoxylin and eosin. Neutrophils, eosinophils and mononuclear cells were separated by Percoll density gradient centrifugation. Cell nuclei were isolated by a rapid cell-breakage and fractionation method. In a typical experiment mean grain densities [grains/100 mu m(2) (ESD)] over cells were: eosinophils 31.2 (18.4), neutrophils 3.5 (3.5), mononuclear cells 4.2 (5.1). Mean grain numbers per cell (ESD) were: eosinophils 13 (6.8), neutrophils 1.3 (1.3), mononuclear cells 1.1 (1.3). These findings were confirmed by separation of labelled leucocytes on discontinuous density gradients. In four separation experiments, the mean activity-per-cell ratio for eosinophils to neutrophils was 10.1 (4.8):1, and for eosinophils to mononuclear cells, 14.1 (6.7):1. The subcellular distribution of the label was investigated using image analysis of autoradiographs and cell fractionation. This revealed no selectivity for nuclear or extranuclear compartments. It may be concluded that Tc-99m-Exametazime has strong selectivity for eosinophils over other leucocytes but no selectivity for nuclear/cytoplasmic compartments.

Item Type: Article
Uncontrolled keywords: leukocytes; technetium-99m-exametazime; microautoradiography; eosinophils
Subjects: R Medicine
Divisions: Faculties > Science Technology and Medical Studies > School of Biosciences
Depositing User: O.O. Odanye
Date Deposited: 10 Jun 2009 07:52
Last Modified: 09 May 2012 09:08
Resource URI: http://kar.kent.ac.uk/id/eprint/19965 (The current URI for this page, for reference purposes)
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