. 2017 Aug 1;8:63. doi: 10.1186/s40104-017-0194-0

Table 4.

Effects of methionine on the activities of trypsin, lipase and amylase in the intestine, Na⁺/K⁺-ATPase, alkaline phosphatase (AKP), γ-glutamyl transpeptidase (γ-GT) and creatine kinase (CK) in the proximal intestine (PI), mid intestine (MI) and distal intestine (DI) of sub-adult grass carp¹

Met, g/kg diet	2.21	4.24	6.22	8.25	10.24	12.26
Trypsin, U/mg protein	170.42 ± 8.13^a	235.75 ± 7.31^b	298.06 ± 5.53^e	275.83 ± 5.93^d	265.32 ± 9.89^c	263.54 ± 7.52^c
Lipase, U/g protein	26.92 ± 1.58^a	28.54 ± 2.21^a	44.78 ± 4.82^b	28.54 ± 2.59^a	29.31 ± 3.12^a	27.24 ± 2.28^a
Amylase, U/mg protein	1.78 ± 0.09^a	1.95 ± 0.08^b	1.90 ± 0.06^b	1.88 ± 0.09^b	1.90 ± 0.03^b	1.94 ± 0.04^b
Na⁺/K⁺-ATPase, μmol pi/mg protein per hour
PI	0.56 ± 0.03^ab	0.56 ± 0.04^ab	0.66 ± 0.06^c	0.62 ± 0.04^bc	0.74 ± 0.09^d	0.51 ± 0.02^a
MI	0.52 ± 0.04^bc	0.55 ± 0.05^bcd	0.56 ± 0.04^cd	0.59 ± 0.05^d	0.50 ± 0.04^b	0.44 ± 0.03^a
DI	0.41 ± 0.03^a	0.43 ± 0.04^ab	0.47 ± 0.05^b	0.40 ± 0.04^a	0.40 ± 0.04^a	0.39 ± 0.04^a
AKP, U/g protein
PI	95.50 ± 10.36^a	114.14 ± 8.49^b	187.58 ± 20.75^e	167.47 ± 13.52^d	167.87 ± 14.96^d	133.74 ± 13.56^c
MI	37.84 ± 4.02^a	51.76 ± 5.44^b	52.45 ± 4.17^b	75.72 ± 7.24^c	71.65 ± 7.42^c	72.29 ± 8.36^c
DI	43.89 ± 2.68^a	46.89 ± 2.70^ab	48.87 ± 2.51^bc	59.24 ± 3.37^d	51.74 ± 3.38^c	44.72 ± 3.75^a
γ-GT, U/g protein
PI	3.62 ± 0.18^a	8.55 ± 0.28^e	6.83 ± 0.36^d	5.89 ± 0.36^c	5.92 ± 0.24^c	4.92 ± 0.18^b
MI	5.01 ± 0.39^a	7.01 ± 0.22^c	7.07 ± 0.40^c	5.62 ± 0.32^b	5.56 ± 0.22^b	4.79 ± 0.16^a
DI	0.52 ± 0.04^a	1.69 ± 0.14^b	2.07 ± 0.13^c	2.21 ± 0.17^c	2.19 ± 0.13^c	2.18 ± 0.16^c
CK, U/mg protein
PI	1.91 ± 0.21^a	2.28 ± 0.19^b	3.75 ± 0.25^d	3.63 ± 0.37^cd	3.41 ± 0.37^c	2.17 ± 0.22^ab
MI	1.65 ± 0.13^e	1.46 ± 0.14^d	0.91 ± 0.09^c	0.71 ± 0.05^b	0.54 ± 0.04^a	0.59 ± 0.07^a
DI	3.43 ± 0.18	3.36 ± 0.27	3.37 ± 0.17	3.24 ± 0.36	3.29 ± 0.34	3.27 ± 0.26
Regressions
Y _Trypsin = −2.768X² + 47.626X + 84.338				R ² = 0.878		P = 0.042
Y _Na ⁺ _/K ⁺ _{-ATPase in MI} = −0.004X² + 0.047X + 0.428				R ² = 0.893		P = 0.035
Y _{AKP in PI} = −2.452X² + 40.210X + 10.672				R ² = 0.822		P = 0.075
Y _{AKP in MI} = −0.378X² + 9.100X + 18.654				R ² = 0.886		P = 0.038
Y_{γ-GT in DI} = −0.033X² + 0.622X – 0.561				R ² = 0.953		P = 0.010
Y_{CK in PI} = −0.065X² + 1.011X – 0.264				R ² = 0.852		P = 0.057
Y_{CK in MI} = 0.012X²–0.291X + 2.313				R ² = 0.962		P = 0.007

^a-eMeans in the same row with different superscript letters differ significantly (P < 0.05)

¹Values are mean ± SD (n = 6)