Response of rhogocytes to deprivation of food and cadmium stress.

<p>Electron micrographs of mantle tissue sections from <i>L</i>. <i>stagnalis</i> after starvation (A,B) and experimental cadmium contamination (C-F). (<b>A</b>) Total view of a rhogocyte from a snail deprived of food for 96 h. The insert (white box) shows that the cell surface is rather plain in that areas with invaginations and slit apparatus are rarely seen. The area within the black frame is magnified in (B). <b>(B)</b> Close-up of the indicated area in (A). Note the high number of small endomembrane compartments filled with a pseudo-crystalline hemocyanin array (arrows). The insert in (B) shows a further enlargement with top views of the hemocyanin stacks. (<b>C</b>) Total view of a rhogocyte from a cadmium-contaminated snail (48 h, 0.05mg/ml of CdCl₂). The framed area is magnified in (D). (<b>D</b>) Close-up of the area framed in (C). Note many electron-dense granula (g) and mitochondria (mi). (<b>E</b>) A cluster rhogocytes from a cadmium-contaminated snail (96 h, 0.1mg/ml of CdCl₂). The three small ovoid rhogocytes might stem from recent cell divisions. The larger rhogocyte with an irregular shape seems to be active in decontamination, as deduced from the framed area magnified in (F). (<b>F</b>) Close-up of the area framed in (E), showing a deeply folded cell surface with slit apparatus, suggesting exceptionally high ultrafiltration rates exhibited by this cell.