Transcriptional responses of xenobiotic metabolizing enzymes, HSP70 and Na+/K+ -ATPase in the liver of rabbitfish (Siganus oramin) intracoelomically injected with amnesic shellfish poisoning toxin.
Amnesic shellfish poisoning toxin domoic acid (DA) is a marine neurotoxin that accumulates in fish and shellfish, and has been implicated to be involved in human and marine wildlife mortality. The transcriptional responses of cytochrome P-450 1A (CYP1A), glutathione S-transferase alpha (GSTA), glutathione S-transferase rho (GSTR), heat shock protein 70 (HSP70), and Na(+)/K(+)-ATPase alpha 1 (ATP1A1) in the liver of rabbitfish (Siganus oramin) intracoelomically injected with DA, were investigated. Experimental fish were administered with one injection of DA (2 microg/g wet weight) or PBS as control. After 24 h, fish were killed and hepatic RNA was isolated. Partial cDNA of rabbitfish CYP1A, GSTA, GSTR, HSP70, ATP1A1, and beta-actin were obtained by PCR using degenerate primers. Using beta-actin as an external control, the relative liver CYP1A, GSTA, GSTR, HSP70, and ATP1A1 mRNA abundance of rabbitfish were determined by semi-quantitative RT-PCR within the exponential phase. The ratio CYP1A/beta-actin mRNA (%) of exposure group was determined to be 148.92+/-12.69, whereas the ratio of control group was 82.3+/-8.35, indicating that CYP1A was induced significantly in rabbitfish following DA exposure (P<0.05). Although the expressions of GSTA, HSP70, and ATP1A1 tended to increase and GSTR tended to decrease, no significant changes were found (P>0.05). The induction of hepatic CYP1A in response to DA suggests a potential role for fish phase I xenobiotic metabolizing enzyme in DA metabolism.
Wang
Lin
L
Department of Biotechnology, College of Life Science and Technology, Jinan University, Shipai, Guangzhou 510632, People's Republic of China.
Liang
Xu-Fang
XF
Huang
Yan
Y
Li
Shi-Ying
SY
Ip
Kok-Chao
KC
D000818:Animals; D019363:Cytochrome P-450 CYP1A1 / Q000235:genetics*; D018076:DNA, Complementary / Q000235:genetics; D005982:Glutathione Transferase / Q000235:genetics*; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics*; D007527:Isoenzymes / Q000235:genetics*; D007608:Kainic Acid / Q000031:analogs & derivatives* / Q000633:toxicity; D008099:Liver / Q000378:metabolism; D008387:Marine Toxins / Q000633:toxicity*; D010473:Perciformes / Q000235:genetics*; D010802:Phylogeny; D000254:Sodium-Potassium-Exchanging ATPase / Q000235:genetics*; D014158:Transcription, Genetic
D018076:DNA, Complementary; D018840:HSP70 Heat-Shock Proteins; D007527:Isoenzymes; D008387:Marine Toxins; D019363:Cytochrome P-450 CYP1A1; D005982:Glutathione Transferase; C119995:glutathione S-transferase alpha; D000254:Sodium-Potassium-Exchanging ATPase; C012301:domoic acid; D007608:Kainic Acid