Ja. Nott et al., CADMIUM IN THE GASTROPOD LITTORINA-LITTOREA, Journal of the Marine Biological Association of the United Kingdom, 73(3), 1993, pp. 655-665
Tissues of Littorina littorea (Mollusca: Gastropoda) were processed fo
r electron microscopy with an aqueous fixative which included hydrogen
sulphide to precipitate intracellular cadmium. The procedure retained
cadmium in the cytosol, where it was below the detection limit for x-
ray microanalysis, but it did not increase the retention of the metal
within lysosomes and other sites of accumulation where it was detectab
le. Aqueous fixation caused extraction of labile elements, particularl
y magnesium and potassium, and this effect was increased by the use of
hydrogen sulphide. Cadmium and hydrogen sulphide had disruptive effec
ts on the fine structure of cells. It is concluded that cytological fi
xatives should not include hydrogen sulphide, and that cryo-fixation i
s required for x-ray microanalysis of intracellular elements. Sites of
intracellular accumulation of cadmium are described. A scheme is prop
osed to show the distribution of the metal between tissues and to acco
unt for the slow rate of loss from the animal.