Destabilized lysosomes and elimination of polycyclic aromatic hydrocarbons and polychlorinated biphenyls in eastern oysters (Crassostrea virginica)

Contaminated oysters from near the Galveston Bay Ship Channel ([GBSC], TX, USA) were transplanted into clean aquariums in order to investigate the recovery of their lysosomal health. Destabilized lysosomes in the oyster hemocytes recovered from 81% to 34% after 23 d of elimination. Chemical analyses showed that transplanted oysters eliminated organic chemicals they had accumulated in their tissue. Enhanced lysosomal health (i.e., decreased lysosomal destabilization) was correlated positively with lower tissue concentrations of chemicals. This study indicates that lysosomal destabilization is a transient biomarker, which indicates only the current status (e.g., within one month) of chemical exposure and potential adverse biological effects. Analytical measurements revealed that polycyclic aromatic hydrocarbons (PAHs) generally were eliminated faster than polychlorinated biphenyls (PCBs) by a factor of 5 to 7. Body burdens of PCBs decreased exponentially, while the elimination pattern of PAHs were biphasic, representing a faster elimination during the early phase of elimination and, subsequently, a much slower elimination. This indicates that elimination of PAHs in the oysters is more complex and may include additional mechanisms compared to the uptake and elimination of PCBs.