QUANTITATIVE AUTORADIOGRAPHY WITH RADIOPHARMACEUTICALS .2. APPLICATIONS IN RADIOPHARMACEUTICAL RESEARCH - CONCISE COMMUNICATION

  • 1 January 1983
    • journal article
    • research article
    • Vol. 24  (3) , 238-244
Abstract
The application of macroautoradiography in mice, a relatively simple, quantifiable method for the evaluation of positron-emitting and gamma-emitting radiopharmaceuticals [14C-2-deoxy-D-glucose [14C-2DG] and 18F-2-fluoro-2-deoxy-D-glucose [18F-FDG]] was described. The response properties of 2 types of film to positron (18F) and negatron (14C) emitters were investigated. Variations in the response of film to increasing film-to-source distance are described, along with the effects of different intensifying screens and mounting tape. Digitization of whole-body autoradiograms (WBARG) in small animals was performed by using a videodensitometry system (videocamera interfaced to a computer). Quantitation was derived from analysis of a series of step-wedge standards that covered the range of radioactivities in the sample. By using a close-up lens on the videocamera, a 2- by 2-cm field is digitized as a 128 .times. 128 array, each pixel representing 156 .times. 156 .mu.m. The effect of chlorpromazine (CPZ) on glucose metabolism in mice was studied by giving 14C-2DG followed by CPZ and 18F-FDG in the same animal. Muscle activity decreased and brown-fat activity increased. The high spatial resolution of this technique enables quantification in structures as small as the basal ganglia in mice. The use of dual-nuclide ARG permits each animal to be its own control, which greatly increases the utility of this method.