» Articles » PMID: 20005581

Catalytic and Immunochemical Detection of Hepatic and Extrahepatic Microsomal Cytochrome P450 1A1 (CYP1A1) in White-sided Dolphin (Lagenorhynchus Acutus)

Overview
Journal Aquat Toxicol
Specialties Biology
Toxicology
Date 2009 Dec 17
PMID 20005581
Citations 1
Authors
Affiliations
Soon will be listed here.
Abstract

We have characterized microsomal systems and measured the levels of microsomal cytochrome P450 1A1 (CYP1A1) and ethoxyresorufin-O-deethylase (EROD) activity in multiple internal organs of male and female white-sided dolphin (Lagenorhynchus acutus) from the northwest Atlantic Ocean. Internal organs were sampled within 24h of death, sometimes in a period of hours, collection times which are significantly less than usually seen for marine mammals. Tissue autolysis, as assessed by histological analysis of liver, was minimal to none in all individuals. Total P420 did not correlate with time from death to sampling, suggesting that it is a poor indicator of P450 degradation in cetacean tissues where perfusion is not practical. The total hepatic microsomal P450 content, cytochrome b5 content, and NADPH-cytochrome c (P450) reductase (CPR) activity averaged 0.29nmolmg(-1), 0.12nmolmg(-1), and 238nmolmg(-1)min(-1), respectively. Microsomal CPR activity in liver was higher than that in lung and kidney, and was higher than that reported in liver of most other cetacean species. Immunodetected CYP1A1 content was low in all organs, less than 3pmolesCYP1A equivalentsmg(-1). EROD activity ranged from 9 to 376pmolesmg(-1)min(-1) and was greater in liver than in other tissues. Hepatic microsomal EROD activity and CYP1A1 content did not correlate. However, hepatic EROD activity, but not CYP1A1 protein content, was well correlated with both total PCB and Sigmamono-ortho PCB concentrations in blubber. Length, as a proxy for age, did not correlate with hepatic EROD activity or CYP1A1 protein levels, and sex did not influence the relationship between EROD and contaminant concentrations. We cannot easily control for the extent of tissue degradation in cetacean studies nor do we have a complete history of these animals. Therefore, other factors such as degradation or hormonal state may have a role in the observed relationships. Yet, as in other mammals, hepatic tissues appear to be a major site of CYP1A1 expression and probably of biotransformation of CYP1A substrates in white-sided dolphin. The expression of an EROD catalyst in liver likely reflects induction by PCBs, but the P450 enzyme catalyzing hepatic EROD activity in these whales may not be CYP1A1.

Citing Articles

Cytochrome P4501A1 expression in blubber biopsies of endangered false killer whales (Pseudorca crassidens) and nine other odontocete species from Hawai'i.

Foltz K, Baird R, Ylitalo G, Jensen B Ecotoxicology. 2014; 23(9):1607-18.

PMID: 25134676 DOI: 10.1007/s10646-014-1300-0.

References
1.
Tuerk K, Kucklick J, McFee W, Pugh R, Becker P . Factors influencing persistent organic pollutant concentrations in the Atlantic white-sided dolphin (Lagenorhynchus acutus). Environ Toxicol Chem. 2005; 24(5):1079-87. DOI: 10.1897/04-120r.1. View

2.
Birkun Jr A, Kuiken T, Krivokhizhin S, Haines D, Osterhaus A, van de Bildt M . Epizootic of morbilliviral disease in common dolphins (Delphinus delphis ponticus) from the Black sea. Vet Rec. 1999; 144(4):85-92. DOI: 10.1136/vr.144.4.85. View

3.
Omura T, Sato R . THE CARBON MONOXIDE-BINDING PIGMENT OF LIVER MICROSOMES. I. EVIDENCE FOR ITS HEMOPROTEIN NATURE. J Biol Chem. 1964; 239:2370-8. View

4.
Drahushuk A, McGarrigle B, Larsen K, Stegeman J, Olson J . Detection of CYP1A1 protein in human liver and induction by TCDD in precision-cut liver slices incubated in dynamic organ culture. Carcinogenesis. 1998; 19(8):1361-8. DOI: 10.1093/carcin/19.8.1361. View

5.
Wilson J, Cooke S, Moore M, Martineau D, Mikaelian I, Metner D . Systemic effects of arctic pollutants in beluga whales indicated by CYP1A1 expression. Environ Health Perspect. 2005; 113(11):1594-9. PMC: 1310924. DOI: 10.1289/ehp.7664. View