CHANGES OF CHOLINESTERASE AND CARBOXYLESTERASE ACTIVITIES IN MALE GUPPIES, Poecilia reticulate, AFTER EXPOSURE TO AMMONIUM PERFLUOROOCTANOATE, BUT NOT TO PERFLUOROOCTANE SULFONATE

The objective of this study was to investigate effects of ammonium perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS) on cholinesterase (ChE) and carboxylesterases (CbE) activities of male guppies in both in vivo and in vitro experiments. Neither in vivo nor in vitro exposure to PFOS significantly altered ChE or CbE activities in male guppy. On the other hand, both in vivo and in vitro exposure to PFOA caused significant inhibitions of muscle and head ChE in male guppies. In addition, in vitro exposure to PFOA significantly reduced liver CbE activity but not in vivo exposure. The result of this study provides some evidence that these two compounds may differ in their ability to change ChE and CbE activities.