Accumulation of 241Am in subcellular structures of the hepatopancreas of the lobster Homarus gammarus

Abstract

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 2 4 1~m accumulation within the intracellular constituents of lobster hepatopancreas; the experimental 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 ligands 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 processes which cause a reconcentration of 2 4 1~m into residual bodies.

Seasonal variations in activity concentrations of 99Tc and 137Cs in the edible meat fraction of crabs and lobsters from the central Irish Sea

“…It was suggested that this may be indicative of the uptake of 99 Tc by the ingestion of contaminated foodstuffs and of the role the green gland and hepatopancreas play in the accumulation and elimination of non-essential trace elements. Other studies have demonstrated that the hepatopancreas is a sink for other radionuclides (Paquet et al, 1993;Durand et al, 1994;Chou and Uthe, 1995). Busby et al (1997) also reported that the lowest 99 Tc activity concentrations found were in white meat (muscle).…”