Hepatopancreatic cells of a stone crab Menippe frontalis from Perú: separation, viability study, and evaluation of lipoperoxidation against cadmium contamination.

Crustaceans are frequently used as bioindicators, and changes in their metabolism at the hepatopancreas (HP) level are often followed in these studies. The HP is the site of digestion, absorption, nutrient storage, and toxic metal detoxification, enabling crabs to survive in metal contaminated regions. Cellular damage and high lipid peroxidation (LPO) levels have been found in crab populations under high cadmium (Cd) concentrations. The aim of this work was to separate and characterize the HP cells of the stone crab Menippe frontalis from the Pacific Ocean, Perú (5° 5' 21″ S-81° 6' 51″ W) and to measure the cellular viability and LPO after exposure to the non-essential metal Cd. The HP cells were dissociated by magnetic stirring, with posterior separation by sucrose gradient at concentrations of 10, 20, 30, and 40%. We found the same cell types that were described for other species (e.g., Ucides cordatus, Atlantic Ocean, Brazil). High cellular viability against 1 mmol L-1 of Cd was observed for resorptive (R) cells in 20% sucrose layer (88 ± 8%, *P < 0.05, ANOVA), and blister (B) cells in the 40% sucrose layers (92 ± 7%, *P < 0.05, ANOVA). Cd (1 mmol L-1 ) caused an increase in LPO levels, suggesting that crabs from polluted areas can be affected by toxic metals, generating a physiological stress. The gradient sucrose methodology can be used for different species and results in a similar separation, viability, and cellular identification. The results are a starting point for toxic metal studies for species distributed across different geographic coordinates.