Are red gourami (Colisa labiosa) low xenobiotic metabolizers? Elucidation of in vivo pharmacokinetics of pyrene as a model substrate

• C. labiosus was exposed to pyrene and the pharmacokinetic parameters were measured.
• C. labiosus could absorb pyrene, but velocity of metabolism and excretion were slow.
• These results indicated that C. labiosus is an accumulator of pyrene.
• C. labiosus has unique characteristics with regard to pyrene pharmacokinetics.

Red gourami (Colisa labiosa) have previously been shown to have low levels of pyrene-metabolizing activity. In this study, other pharmacokinetic factors of pyrene in C. labiosa were compared to those in Japanese medaka (Oryzias latipes). Results indicated that the two species labiosa absorbed pyrene in similar amounts. However, excretion of pyrene metabolites from C. labiosa over an 8-day period was lower than those from O. latipes. These findings show that C. labiosa has low ability to metabolize pyrene and to excrete pyrene and its metabolites from the body, and is therefore considered an accumulator of these chemicals. C. labiosa has unique characteristics with regard to pyrene pharmacokinetics. Knowledge about interspecies differences in pharmacokinetics is crucial in determining the endangered species to xenobiotic exposure.