Effects of Methionine Deficiency on Nutrient Composition, No, Nos Activity and Mrna Expression in Nf-κb Signal Pathway of the Liver and Kidney in Broiler

ABSTRACT The study aimed to investigate the effect of methionine deficiency on conventional nutrient composition, NO and NOS activity in the liver and kidney, and expression of genes related to the NF-κB signal pathway. One hundred 1-day-old broilers were divided into control and methionine deficiency group, and provided with a standard diet. The methionine-deficient group was fed with a methionine-deficient diet for 42 days. Moisture content, protein content, and crude lipid content were determined by freeze drying, the Kjeldahl method, and the ether extraction method. The concentration of NO was measured using the nitrate reductase method, and the activity of NOS was measured using colorimetry. mRNA expression of related genes in the NF-κB signal pathway was detected by reverse transcription-polymerase chain reaction (RT-PCR). The results showed the contents of crude protein and crude lipid in the liver and kidney of the methionine-deficient group were significantly higher than those in the control group (p<0.05 or p<0.01). There was no significant change in dry matter (p>0.05). Methionine deficiency resulted in significantly increased NO concentration and total nitric oxide synthase (TNOS) activities in the liver and kidney (p<0.01). In contrast, cNOS and inducible iNOS activities significantly decreased (p<0.01). The expression of NF-κB, TNF-α, IFN-γ, IL-1, and IL-6 mRNA, which are related to the NF-κB signal pathway of the methionine-deficient group, were significantly higher than those in the control group (p<0.05 or p<0.01). It is concluded that long-term feeding diets lacking methionine will lead to changes in nutrient composition and inflammatory injury of the liver and kidney.