ACCUMULATION OF AM-241 IN SUBCELLULAR STRUCTURES OF THE HEPATOPANCREAS OF THE LOBSTER HOMARUS-GAMMARUS

Some of the artificial radionuclides released by the nuclear industry are assimilated by marine organisms. In this study, an attempt is made to elucidate the detailed mechanisms of Am-241 accumulation within th e intracellular constituents of lobster hepatopancreas; the experiment al procedure involved contaminating lobsters with a radiolabelled meal . The monitoring of activity levels in the digestive gland shows that the intracellular incorporation of this radioisotope occurs through a 2-fold process of adsorption onto membranes coupled with endocytosis, taking place within 30 min of ingestion. The breakdown of exogenous li gands releases americium, which then appears to be distributed between subcellular structures via the mediation of a cytosolic vector. After 24 h, various cellular constituents are affected by autophagous proce sses which cause a reconcentration of Am-241 into residual bodies.