Sammanfattning

The study investigated the kinetics of p-nitrophenol hydroxylase (PNPH) in hepatic microsomes obtained from Atlantic salmon (Salmo salar). The selective inhibitors for some major mammalian cytochrome P450 (CYP450) were used to investigate the potential inhibitory effect on enzymes involved in p-nitrophenol hydroxylation. The following inhibitors were used: alpha-naphtoflavone (CYP1A), ellipticine (CYP1A1), furafylline (CYP1A2), 8-methoxypsoralen (8MOP, CYP2A6), 4-methylpyrazole (4MP, CYP2A6/2E1), diallyl sulfide (DAS, CYP2E1), and ketoconazole (CYP3A4). Additionally, the natural steroids 17-beta-oestraiol (E2) and testosterone were investigated as potential inhibitors of PNPH activity. It was found that formation of 4-nitrocatechol from p-nitrophenol followed monophasic kinetics with K (m) = 0.17 +/- A 0.03 mM and V (max) = 21.8 +/- A 1.05 pmol/min/mg. PNPH activity was competitively inhibited by diallyle sulfide with the K (i) value of 285.1 +/- A 94.2 mu M mu M and uncompetitively by ellipticine with K (i) value of 65.7 +/- A 7.8 mu M. Moreover, E2 showed an ability to reduce PNPH activity through the mechanism-based inhibition mode. Our results suggest that hepatic microsomes from Atlantic salmon possess CYP2E1-like activity. However, specific isoform-mediated PNPH activity should be identified.

Nyckelord

Atlantic salmon; Hepatic microsomes; P-nitrophenol; Diallyl sulfide; Ellipticine

Publicerad i

Fish Physiology and Biochemistry
2011, Volym: 37, nummer: 4, sidor: 969-976
Utgivare: SPRINGER

SLU författare

• Zamaratskaia, Galia

  • Institutionen för molekylära vetenskaper, Sveriges lantbruksuniversitet
    

• Zlabek, Vladimir

  • Institutionen för molekylära vetenskaper, Sveriges lantbruksuniversitet
    

UKÄ forskningsämne

Fysiologi
Fisk- och akvakulturforskning
Biokemi och molekylärbiologi


Publikationens identifierare

DOI: https://doi.org/10.1007/s10695-011-9494-z

Permanent länk till denna sida (URI)

https://res.slu.se/id/publ/46244