ISSN:
1432-1793
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Seastars, which are known to accumulate transuranium nuclides to relatively high levels, were used in laboratory radiotracer experiments (April–May, 1982) designed to determine the subcellular distribution of tissue-incorporated californium-252 and americium-241. Mediterranean asteroids (Marthasterias glacialis), collected in April 1982 and fed prey contaminated with 252Cf and 241Am, accumulated and retained large fractions of these radionuclides (252Cf, 91 to 98%; 241Am, 82 to 88%) in their pyloric caeca, the glandular complex involved with digestive and food storage processes. Differential centrifugation demonstrated an association of 252Cf and 241Am with the lysosome-mitochondrial fraction of plyoric caeca cells. Partial separation of lysosomes and mitochondria by isopycnic gradient centrifugation suggests a somewhat different subcellular fractionation of the two transuranics; 252Cf is associated primarily with the mitochondria, whereas 241Am is accumulated in both lysosomes and mitochondria. From comparison with analogous studies in mammalian systems, it is hypothesized that the long biological half-lives reported for ingested transuranics in seastars result in large part from the radionuclide association with mitochondria in the pyloric caeca.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00406010
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