Fig. 2. Effects of Cd exposure on aconitase activity in intact (A) and permeabilized (B) mitochondria of oysters Crassostrea virginica. Cd was either incubated with intact mitochondria (A), or directly added to Triton X-100 permeabilized mitochondria (B). ^*Values significantly different from the respective controls (P<0.05). Aconitase activity in B is presented as a percentage of the respective control values. Cd added to permeabilized mitochondria had no effect on aconitase activity (P>0.28). N=5-11, except for 10 µmol l^-1 and 75 µmol l^-1 Cd (N=3-4).