The Company of Biologists

Table 2.

Effect of dietary L-tryptophan (TRP) and stress on the plasma concentration of TRP and large neutral amino acids (LNAA), and ratios of TRP to LNAA concentrations in blood plasma of rainbow trout

		Plasma
Feed	Treatment	[TRP] (mg ml^-1)	[LNAA] (mg ml^-1)	[TRP]/[LNAA]
1×	Non-stressed	0.06±0.005^a	24.44±3.59^a	0.0024±0.0005^a
	Stressed	0.06±0.03^a	24.73±5.59^a	0.0025±0.0002^a
2×	Non-stressed	0.12±0.20^a	21.59±4.84^a	0.0054±0.0007^a
	Stressed	0.09±0.018^a	34.09±11.34^a	0.0027±0.0012^a
4×	Non-stressed	0.44±0.17^a	21.71±5.39^a	0.0202±0.0032^a
	Stressed	0.49±0.18^a,b	39.59±22.59^a	0.0124±0.0110^a,b
8×	Non-stressed	0.72±0.18^b	33.98±14.89^a	0.0214±0.0350^b
	Stressed	1.02±0.28^b	19.54±2.22^a	0.0521±0.0180^b

		Plasma
Feed	Treatment	[TRP] (mg ml^-1)	[LNAA] (mg ml^-1)	[TRP]/[LNAA]
1×	Non-stressed	0.06±0.005^a	24.44±3.59^a	0.0024±0.0005^a
	Stressed	0.06±0.03^a	24.73±5.59^a	0.0025±0.0002^a
2×	Non-stressed	0.12±0.20^a	21.59±4.84^a	0.0054±0.0007^a
	Stressed	0.09±0.018^a	34.09±11.34^a	0.0027±0.0012^a
4×	Non-stressed	0.44±0.17^a	21.71±5.39^a	0.0202±0.0032^a
	Stressed	0.49±0.18^a,b	39.59±22.59^a	0.0124±0.0110^a,b
8×	Non-stressed	0.72±0.18^b	33.98±14.89^a	0.0214±0.0350^b
	Stressed	1.02±0.28^b	19.54±2.22^a	0.0521±0.0180^b

Fish were fed feeds supplemented with TRP to a level corresponding to two(2×), four (4×) and eight (8×) times the TRP content of non-supplemented control feed (1×) for 7 days.

Stressed fish were exposed to a standarised stressor (lowering the water level); controls were undisturbed fish that were kept isolated.

Different superscript letters indicate significant difference at the level of P<0.05 (LSD-test).

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