Table 4. Plasma biochemical markers of organ function and stress of Atlantic salmon (Salmo salar L.) exposed to graded levels of ethoxyquin (EQ) through their diet for 90 days.

	Dietary treatment
Markers of organ function	EQ 0	EQ 1	EQ 2	EQ 3	EQ 4	EQ 5	P-values
Albumin (umol/l)	344.79 ± 30.02	326.25 ± 24.49	347.29 ± 19.04	362.88 ± 31.21	350.07 ± 35.00	286.94 ± 59.73	< .05
ALT (U/l)	12.81 ± 9.92	14.24 ± 5.74	21.54 ± 13.09	18.84 ± 13.13	13.19 ± 9.25	3.60 ± 2.99	< .05
AST (U/l)	431.78 ± 106.55	459.85 ± 149.48	456.40 ± 85.51	412.63 ± 129.22	411.02 ± 165.32	266.68 ± 110.86	0.54
Bilirubin (umol/l)	1.60 ± 0.32	1.56 ± 0.49	1.41 ± 0.38	1.69 ± 0.33	2.05 ± 0.51	2.06 ± 0.28	< .01
Bile acids (umol/l)	1.80 ± 0.98	5.01 ± 4.14*	4.37 ± 3.81	2.85 ± 2.27	2.51 ± 1.23	1.57 ± 0.31	< .05
Total protein (g/l)	48.04 ± 4.64	45.84 ± 4.61	48.40 ± 3.21	48.17 ± 5.01	46.27 ± 5.23	36.68 ± 7.58*	< .01
Creatinine (umol/l)	22.13 ± 5.62	19.35 ± 5.53	19.29 ± 4.47	12.20 ± 2.53*	9.57 ± 2.38*	8.64 ± 1.64*	< .0001
Na+	172.40 ± 3.38	172.20 ± 2.91	171.60 ± 2.17	173.07 ± 3.08	171.40 ± 3.11	172.40 ± 4.22	0.95
K+	2.18 ± 0.90	2.25 ± 0.68	2.56 ± 0.98	2.07 ± 0.95	2.12 ± 0.60	1.85 ± 0.80	0.64
Ca2+	1.75 ± 0.09	1.78 ± 0.05	1.74 ± 0.08	1.76 ± 0.05	1.76 ± 0.07	1.79 ± 0.11	0.71
Cl-	146.93 ± 2.46	147.87 ± 2.88	147.53 ± 1.77	148.13 ± 2.72	146.80 ± 2.27	147.07 ± 3.85	0.75
Osmolality (mOsmol/l)	349.27 ± 12.05	351.07 ± 8.04	350.00 ± 6.53	349.40 ± 9.97	349.33 ± 11.17	344.80 ± 11.55	0.93

Measurements performed on five replicate measurements from the individual tanks (n = 3/group). A nested ANOVA was fit using a mixed effects model with tank treated as a random effect, and post-hoc comparison of least-square group means adjusting for multiple comparisons. Results are presented as means ± SD of all measurements.

* p<0.05, compared to the control (EQ 0).

Abbreviations: ALT; Alanine aminotransferase. AST; Aspartate aminotransferase.