Beluga whale liver microsomal cytochrome P4501A (CYP1A) enzymes
Conference
·
OSTI ID:392314
- Inst. of Ocean Sciences, Sidney, British Columbia (Canada)
- Dept. of Fisheries and Oceans, Winnipeg, Manitoba (Canada)
Beluga whale (Delphinapterus leucas) liver from the Canadian arctic was analyzed for the presence of CYP1A enzymes, as part of current studies on biomarkers for environmental contamination. CYP1A1-associated 7-ethoxyresorufin O-dealkylase activity (EROD) varied 13 fold among sixteen male whale liver microsomal samples and 31 fold among five females. Similarly, the rate of 7-methoxyresorufin O-dealkylation (MROD) varied 7 fold and 3 fold in microsomal samples from males and females, respectively. Furthermore, 7-pentoxyresorufin O-dealkylase activity (PROD) varied 10 fold in both sexes. None of these enzyme activities were sexually differentiated, and EROD and MROD were inhibited by {alpha}-naphthoflavone. There was very good correlation between EROD and MROD (r{sup 2} = .894), EROD and PROD (r{sup 2} = .909), but MROD and PROD were not as well correlated (r{sup 2} = 785). On Western immunoblots, a single band was recognized in Beluga whale liver microsomes by a polygonal antibody raised against an oligopeptide related to trout CYP1A1. This antibody also recognized purified rat CYP1A1 (56 kDa) and stained only one band (56 kDa) in liver microsomes isolated from male rats treated with {beta}-naphthoflavone. The interindividual variation in EROD paralleled differences in the amount of whale liver microsomal protein that cross-reacted with the anti-peptide antibody. The results suggest that Beluga whale liver contains at least one CYP1A enzyme which catalyzes the 0-dealkylation of 7-ethoxy, 7-methoxy and 7-pentoxyresorufin and has a molecular weight less than that of rat CYP1A1, but similar to rat CYP1A2 (52 kDa).
- OSTI ID:
- 392314
- Report Number(s):
- CONF-9511137--; ISBN 1-880611-03-1
- Country of Publication:
- United States
- Language:
- English
Similar Records
Induction of hepatic CYP1A in male F344/NCr rats by dietary exposure to Aroclor 1254: Examination of immunochemical, RNA, catalytic, and pharmacokinetic endpoints
Inactivation of channel catfish CYP1A by 2-aminoanthracene
Sequencing and characterization of mixed function monooxygenase genes CYP1A1 and CYP1A2 of Mink (Mustela vison) to facilitate study of dioxin-like compounds
Conference
·
Mon Nov 30 23:00:00 EST 1992
· Environmental Research; (United States)
·
OSTI ID:6713394
Inactivation of channel catfish CYP1A by 2-aminoanthracene
Conference
·
Sat Dec 30 23:00:00 EST 1995
·
OSTI ID:392320
Sequencing and characterization of mixed function monooxygenase genes CYP1A1 and CYP1A2 of Mink (Mustela vison) to facilitate study of dioxin-like compounds
Journal Article
·
Sat Jan 31 23:00:00 EST 2009
· Toxicology and Applied Pharmacology
·
OSTI ID:21182717