Ocean acidification: synergistic inhibitory effects of protons and heavy metals on Ca uptake by lobster branchiostegite membrane vesicles.

Previous work with isolated outer membrane vesicles of lobster branchiostegite epithelial cells has shown that Ca uptake by these structures is significantly (p < 0.02) reduced by an incremental decrease in saline pH (increased proton concentration) and that this decrease is due to competitive inhibition between carrier-mediated transport of Ca and hydrogen ions. The present paper extends these previous findings and describes the combined effects of pH and cationic heavy metals on branchiostegite uptake of Ca.