Effects of zinc (Zn) and copper (Cu) on cadmium (Cd) accumulation were investigated in LLC-PK1 cells. Coincubation with Zn or Cu decreased Cd uptake by the cells in a concentration-dependent manner. Cd accumulation data suggested that Cd is taken up by the cells via simple diffusion and carrier-mediated transport. Zn and Cu significantly increased the Km of Cd uptake with no or little effect on the Vmax. Pretreatment of the cells with ouabain and a metabolic inhibitor (FCCP) significantly decreased Cd accumulation, and coincubation with Zn or Cu led to an additional decrease in Cd accumulation by these cells. Overall, it seems that, in addition to simple diffusion, Cd is also taken up by LLC-PK1 cells via carrier-mediated mechanisms that are competitively inhibited by Zn and Cu.
We studied δ13C, δ15N, δ18O, and Hg in muscles from deep-sea predators—five beaked whale species and sperm whales—stranded in Japan. The δ13C, δ15N, δ18O, Hg, and body length (BL) of Stejneger’s beaked whales were similar to those of Hubbs’ beaked whales, which belong to the same genus. However, these values for Sato’s beaked whales were markedly different from those of Baird’s beaked whales, which belong to the same genus. The δ13C in combined samples from all whales increased with increasing BL, probably owing to the larger whale species’ dietary preference for squid. The δ13C in combined samples from all whales was positively correlated with Hg, whereas the δ15N was negatively correlated. The δ18O in combined samples from most whales tended to be positively correlated with Hg. A higher Hg load from deep-sea feeding than from pelagic feeding and a feeding shift toward lower trophic levels may explain these correlations.
'/%3e%3cuse xlink:href='%23a' transform='rotate(72 0 0)'/%3e%3cuse xlink:href='%23a' transform='rotate(-72 0 0)'/%3e%3cuse xlink:href='%23a' transform='scale(-1 1) rotate(72)'/%3e%3c/g%3e%3c/defs%3e%3cpath fill='%23012169' d='M0 0h1200v600H0z'/%3e%3cpath stroke='%23FFF' stroke-width='60' d='m0 0 600 300M0 300 600 0' clip-path='url(%23b)'/%3e%3cpath stroke='%23C8102E' stroke-width='40' d='m0 0 600 300M0 300 600 0' clip-path='url(%23c)'/%3e%3cpath stroke='%23FFF' stroke-width='100' d='M300 0v300M0 150h600' clip-path='url(%23b)'/%3e%3cpath stroke='%23C8102E' stroke-width='60' d='M300 0v300M0 150h600' clip-path='url(%23b)'/%3e%3cuse xlink:href='%23d' fill='%23FFF' transform='matrix(45.4 0 0 45.4 900 120)'/%3e%3cuse xlink:href='%23d' fill='%23C8102E' transform='matrix(30 0 0 30 900 120)'/%3e%3cg transform='rotate(82 900 240)'%3e%3cuse xlink:href='%23d' fill='%23FFF' transform='rotate(-82 519.022 -457.666) scale(40.4)'/%3e%3cuse xlink:href='%23d' fill='%23C8102E' transform='rotate(-82 519.022 -457.666) scale(25)'/%3e%3c/g%3e%3cg transform='rotate(82 900 240)'%3e%3cuse xlink:href='%23d' fill='%23FFF' transform='rotate(-82 668.57 -327.666) scale(45.4)'/%3e%3cuse xlink:href='%23d' fill='%23C8102E' transform='rotate(-82 668.57 -327.666) scale(30)'/%3e%3c/g%3e%3cuse xlink:href='%23d' fill='%23FFF' transform='matrix(50.4 0 0 50.4 900 480)'/%3e%3cuse xlink:href='%23d' fill='%23C8102E' transform='matrix(35 0 0 35 900 480)'/%3e%3c/svg%3e)