Our previous studies have thrown new light on
the TTX uptake mechanism in puffer fish liver. The
liver tissue slices of T. rubripes or Takifugu pardalis
accumulated TTX with the incubation time when
they were incubated in TTX-containing medium.
The TTX amount accumulated in the liver slices did
not decrease even when they were further incubated
in the medium without TTX (Nagashima et al.,
2003). In addition, the in vitro incubation assay
showed that liver tissue slices of T. rubripes
specifically accumulate TTX in preference to saxitoxins
(STXs) (Matsumoto et al., 2005). We
recently revealed that the involvement of the
carrier-mediated transport system in the TTX
uptake mechanism of T. rubripes liver strongly
suggest the presence of TTX transporter in the liver,
whereby it actively and selectively concentrates
TTX (Matsumoto et al., 2007).