EARLY ULTRASTRUCTURAL LESIONS IN KIDNEY-C ELLS ALTER INTRAVENOUS ADMINISTRATION OF 239-PLUTONIUM CITRATE IN THE RAT

After intravenous administration of(5 x 2.3 kBq and 5 x 9.25 kBq) plut onium citrate iii! adult male Sprague Dawley rats, their Kidneys are w ithdrawn and prepared for observation under a transmission electron mi croscope. Seven days after the first injections, deep cellular alterat ions are observed in the proximal convoluted tubules. These alteration s are mainly mitochondrial The affected mitochondria are of swollen as pect and have their cristae partially or completely destroyed Neverthe less within the same tubule we observe non altered cells directly in c ontact with deeply altered cells. In all the cases the lysosomes of th e altered cells appear to be perfectly normal The cell nuclei are most ly unaltered but a few cases of nuclear fragmentation exist. We also n otice some architectural modifications in the brush border and in the betacytomembranes of the proximal convoluted tubule. Equally important mitochondrial alterations are also noticed in the different varieties of glomerular cells. We observe no other glomerular alterations. The major subcellular alterations in the proximal convoluted tubules and i n the different varieties of glomerular cell; deeply contrast with the distal convoluted tubules which are found to be totally unaltered. Th ese mitochondrial alterations may be due to the or particle disintegra tion of plutonium which may either directly react with the mitochondri a or, through the products of radiolysis of water react with the mitoc hondria respiration process. However the direct chemotoxicity of pluto nium cannot be neglected.