EFFECT OF NITRITE STRESS ON GENE EXPRESSION OF ANTIOXIDANT ENZYMES, HEAT SHOCK PROTEIN 70, AND METABOLIC ENZYMES IN GILL TISSUE OF ADULT RED SWAMP CRAYFISH, PROCAMBARUS CLARKII

摘要

The effect of acute nitrite stress on gene expression of antioxidant enzymes, Hsp70 and metabolic enzymes in gill tissue of adult Procambarus clarkii (Girard, 1852) was evaluated. A 48 hours nitrite exposure was conducted, using four test concentrations (NO2-N = 1, 2, 3 and 4 mg l(-1)) plus a control group. Significantly increased mRNA expression was observed for all the antioxidant enzymes. A significant increase of Hsp70 mRNA expression was observed when exposed to 2 mg l(-1) nitrite-N at 12 h. An elevation in AST mRNA expression occurred in the 3 mg l(-1) nitrite-N group at 12 h. No significant variation was observed for ALT. Elevations in SDH and Na+/K+-ATPase alpha-subunit mRNA expression were found throughout the experiment. This study shows that gene expression of antioxidant and metabolic enzymes could be helpful in predicting sublethal nitrite toxicity and it will also improve our understanding of the toxicological mechanisms of nitrite on crustacean.