Table 4.

Effects of dietary lysine levels on intestinal antioxidant parameters of grass carp fry (means ± S.E.M.)^a .

Lysinelevels (%)	CAT b (U/mg protein)	SOD c (U/mg protein)	MDA d (nmol/mg protein)	GSH e (μmol/g protein)	GPx f (U/mg protein)
1.44	1.10 ± 0.30 a	0.38 ± 0.04	1.13 ± 0.37	8.65 ± 1.49	16.19 ± 1.71 a
1.79	1.70 ± 0.54 a	0.38 ± 0.02	1.09 ± 0.32	7.73 ± 1.52	24.24 ± 2.43 a b
1.97	3.06 ± 0.43 a b	0.49 ± 0.02	1.00 ± 0.44	12.10 ± 1.82	24.59 ± 4.66 a b
2.44	3.92 ± 0.70 b	0.48 ± 0.06	0.99 ± 0.20	13.46 ± 1.74	35.52 ± 7.51 b
2.56	2.57 ± 0.40 a b	0.43 ± 0.03	0.98 ± 0.40	13.54 ± 2.17	36.51 ± 2.33 b
2.87	1.32 ± 0.30 a	0.37 ± 0.02	1.01 ± 0.13	9.90 ± 2.20	22.86 ± 4.59 a b

^aAll data are means of triplicate, values in the same column with different superscripts are significantly different (P < 0.05).

^bCAT, Catalase.

^cSOD, Superoxide dismutase.

^dMDA, Malondialdehyde.

^eGSH, Glutathione.

^fGPx, Glutathione peroxidase.