Different Effects of Sheep- and Duck-Meat Supplemented Diets on Serum Cytokine Levels of Rats

Abstract

This study aimed to explore the mechanism underlying the different effects of diet supplemented with sheep- or duck-meat on serum cytokines of rats. Methods: Male Sprague-Dawley rats were randomly divided into three groups fed on sheep meat, duck meat, or soybean, respectively. The profiles of amino acids and fatty acids of the three diets were examined, and the levels of serum cytokines in rats, including interleukin-1β (IL-1β), IL-2, IL-4, IL-6, IL-10 and tumor necrosis factor-α (TNF-α), were detected 30 d after feeding, using radioimmunoassay. The contents of methionine and glycine in the sheep-meat and duck-meat diets were significantly higher than those in the soybean diet. The content of saturated fatty acids in the sheep-meat diet and duck-meat diet was higher than that in soybeans, while the polyunsaturated fatty acids (PUFAs) in the duck-meat diet were highest and those in the sheep-meat diet were lowest. Serum levels of IL-2 and IL-10 in the rats of the sheep-meat and duck-meat groups were significantly higher than those in the rats of the soybean group (p<0.05). IL-10 and TNF-α in the rats of the sheep-meat group were higher than those in the duck-meat group. But the levels of IL-1β and IL-6 were not significantly different among the three groups. Additionally, there were positive correlations between glycine and IL-1β as well as glycine and IL-2, while negative correlation existed between C18:2 and TNF-α. Methionine, glycine and PUFAs in a diet supplemented with sheep- or duck-meat might influence the levels of serum cytokines in rats, suggesting the potential regulatory mechanism of amino acids and fatty acids from diet in immune responses.