The relationship between dietary methionine and growth, digestion, absorption, and antioxidant status in intestinal and hepatopancreatic tissues of sub-adult grass carp (Ctenopharyngodon idella)

Table 6 Effects of methionine on malondialdehyde (MDA), protein carbonyl (PC) content, anti-superoxide anion (ASA) and anti-hydroxy radical (AHR) activities in the hepatopancreas and intestine of sub-adult grass carp¹

Met, g/kg diet	2.21	4.24	6.22	8.25	10.24	12.26
Hepatopancreas
MDA, nmol/mg protein	2.19 ± 0.18^b	2.09 ± 0.10^b	1.15 ± 0.11^a	2.04 ± 0.14^b	2.15 ± 0.15^b	2.08 ± 0.08^b
PC, nmol/mg protein	6.63 ± 0.48^c	3.66 ± 0.31^b	2.56 ± 0.20^a	3.53 ± 0.36^b	3.67 ± 0.29^b	3.63 ± 0.14^b
ASA, U/g protein	197.0 ± 15.3	194.4 ± 8.7	202.9 ± 12.9	205.6 ± 15.2	202.9 ± 16.80	202.5 ± 7.3
AHR, U/mg protein	208.5 ± 8.0^a	229.5 ± 9.7^c	259.7 ± 6.4^e	256.0 ± 10.6^e	244.7 ± 5.90^d	219.3 ± 10.1^b
Intestine
MDA, nmol/mg protein	1.73 ± 0.14^b	1.72 ± 0.17^b	1.44 ± 0.08^a	1.41 ± 0.11^a	1.98 ± 0.12^c	2.09 ± 0.12^c
PC, nmol/mg protein	4.27 ± 0.34^b	3.63 ± 0.36^a	3.16 ± 0.38^a	3.19 ± 0.39^a	3.19 ± 0.26^a	5.30 ± 0.37^c
ASA, U/g protein	213.5 ± 19.0^a	281.6 ± 19.4^b	303.0 ± 24.5^b	284.9 ± 20.7^b	282.1 ± 25.2^b	287.3 ± 23.5^b
AHR, U/mg protein	133.4 ± 8.7^a	173.2 ± 13.0^b	198.1 ± 12.8^c	179.6 ± 11.9^b	175.8 ± 12.8^b	143.2 ± 12.7^a
Regressions
Y _{PC in Hepatopancreas} = 0.087X²–1.455X + 8.910				R ² = 0.773		P = 0.108
Y _{AHR in Hepatopancreas} = −1.757X² + 26.793X + 155.081				R ² = 0.952		P = 0.010
Y _{MDA in Intestine} = 0.018X²–0.219X + 2.181				R ² = 0.745		P = 0.129
Y _{PC in Intestine} = 0.069X²–0.945X + 6.198				R ² = 0.855		P = 0.055
Y _{ASA in Intestine} = −1.819X² + 31.349X + 165.218				R ² = 0.773		P = 0.108
Y _{AHR in Intestine} = −2.108X² + 31.047X + 77.708				R ² = 0.929		P = 0.019

^a-eMeans in the same row with different superscript letters differ significantly (P < 0.05)
¹Values are mean ± SD (n = 6)

ISSN: 2049-1891