Susceptibility to oxyradical toxocity in Antarctic, Arctic, and Mediterranean scallops

We have used the total oxyradical scavenging capacity (TOSC) assay for quantifying the ability of biological samples to neutralize peroxyl (ROO.) and hydroxyl (.OH) radicals and peroxynitrite (PN). TOSC was assessed for three species of scallops, Adamussium colbecki (AC), Chlamys islandicus (CI) and Pecten jacobaeus (PJ), respectively from the Antarctic, Arctic and Mediterranean seas. TOSC values for ROO. were significantly higher in AC indicating that this species is the more efficient scavenger of ROO.. Mediterranean scallops had the lowest TOSC for ROO.. AC had the highest scavenging capacity for .OH; the TOSC value was 3-fold greater than for CI and PJ. TOSC for PN was lower for all scallops as compared to that for ROO. or .OH. TOSC for microsomes was not significantly different among the species for any ROS studied, and the percentage contribution to the specific TOSC for the various oxidants of microsomes of all scallops accounted for 1–3% of the total TOSC of the post-mitochondrial fraction. The specific TOSC of scallop microsomes for .OH was 10 times lower than that for ROO. or PN. TOSC is proposed as a quantifiable value of susceptibility to oxidative stress from aquatic pollution.