QUANTITATIVE COMPARISON OF AUTORADIOLUMINOGRAPHIC AND RADIOMETRIC TISSUE DISTRIBUTION STUDIES USING C-14-LABELED XENOBIOTICS

The tissue distribution of two C-14 drugs were quantitatively compared using the techniques of who re body auto radioradioluminography (WEAL ) and radiometry, Quantitative analysis of tissue radioactivity in who le body cryosections was accomplished from storage phosphor images usi ng the MicroComputer Imaging Device, After obtaining whole body sectio ns from four frozen rats and three frozen ferrets, each WBAL-sectioned specimen was partially thawed before obtaining tissue samples for rad iometric analysis, For all tissues examined, concentrations of radioac tivity determined by WEAL were comparable with those determined by dis section and liquid scintillation analysis (DLSA), except for renal tis sue obtained from different kidneys of the same ferret and for rat ocu lar tissues, A a-fold difference was observed between WEAL and DLSA ev aluations of radioactivity in the contralateral kidneys of one ferret, DLSA evaluation only provided an assessment of total radioactivity in the eye, whereas WEAL evaluation determined the selective distributio n of radioactivity to ocular tissues, Resolution in DLSA evaluation of ocular tissues was restricted by limitations of the dissection proced ure. These results indicated that the quantitation of tissue radioacti vity by WEAL was as precise as DLSA evaluation, and WEAL also provided results to the quantitative distribution of radioactivity to localize d sites in organs not feasible by DLSA.