Xenobiotic Monooxygenase Activity and the Response to Inducers of Cytochrome P-450 during Embryonic and Larval Development in Fish

摘要

Data demonstrating the presence and inducibility of the xenobiotic monooxygenase system in fish embryos and larvae are described. Benzo (a) pyrene monooxygenase (BPM) activity was present in microsomes prepared from whole embryos of Fundulus heteroclitus prior to the appearance of the liver rudiment. This activity was low at all stages prior to hatching, then increased more than 10-fold within 24 hours of hatching. Both No. 2 fuel oil and Aroclor 1254 induced BPM activity in Fundulus embryos. At least 5-fold higher tissue levels of PCBs were required for maximal induction of BPM activity in prehatching stages as compared to posthatching stages. This may serve to protect the most sensitive developmental stages from damage from activated metabolites. Fish embryonic monooxygenase activity may play a role in pollutant induced teratogenesis and carcinogenesis.