Activity and inducibility of aryl hydrocarbon hydroxylase in the eelpout Zoarces viviparus (L.).

Abstract

The aryl hydrocarbon hydroxylase (AHH) activity in eelpout liver microsomes was determined with14C-naphthalene as substrate. The AHH activity changed with the season, peaking in May in both males and females, and did not correlate to water temperature nor time of ovulation. Starvation for one week did not change the AHH activity; starvation for six months increased the activity slightly (p<0.025). Exposure of 0.5 ppm naphthalene in the water for one week or intraperitoneal injection (ip.) of naphthalene in peanut oil (100 mg/kg) did not induce AHH activity in the liver microsomes of adult female eelpouts, which was in contrast to ip. of 5,6-benzoflavone (5,6-BF) (100 mg/kg) which increased the AHH activity three fold. 7,8-benzoflavone (7,8-BF) inhibited the AHH activityin vitro in 5,6-BF induced fish, but it increased the AHH activity in control fish. The AHH activity in the liver microsomes of eelpout embryos shortly before and shortly after parturition was in the same range as in the mother fish.