高铜对雏鸭胸腺影响的病理学研究

Pathological Study of Effect of Dietary High Copper on the Thymus in Ducklings

本文旨在研究高铜对雏鸭胸腺的病理学影响。选用1日龄天府肉鸭360只,随机分为6组,分别喂以对照日粮(Cu 8 mg/kg)和高铜日粮(Cu 100 mg/kg,高铜Ⅰ组;Cu 200 mg/kg,高铜Ⅱ组;Cu 400 mg/kg,高铜Ⅲ组;Cu600 mg/kg,高铜Ⅳ组;Cu 800 mg/kg,高铜Ⅴ组)6周。与对照组比较,高铜Ⅲ组、高铜Ⅳ组、高铜Ⅴ组雏鸭胸腺出现不同程度的病变,生长指数显著降低(P<0.05或P<0.01),淋巴细胞的静止期增长及增殖指数明显下降(P<0.05或P<0.01),淋巴细胞的调亡率显著升高(P<0.05或P<0.01);高铜Ⅰ组和高铜Ⅱ组雏鸭胸腺上述指标变化不明显。结果表明,日粮铜含量高于400 mg/kg时,不同程度地抑制雏鸭胸腺的发育,导致雏鸭细胞免疫功能受损。

The experiment was conducted with the objective of examining the effects of high copper on the thymus in the duckling by the methods of experimental pathology and flow cytometry （FCM）. 360 one-day-old Tianfu ducklings were randomly divided into six groups, and fed on diets as follows.. Controls （Cu 8 mg/kg） and high copper （Cu 100 mg/kg, high copper group Ⅰ ; Cu 200 mg/kg, high copper group Ⅱ ; Cu 400 mg/kg, high copper group Ⅲ ; Cu 600 mg/kg, high copper group Ⅳ ; Cu 800 mg/kg, high copper group Ⅴ） for six weeks. The results showed that histological changes were observed in high copper copper groups Ⅲ, Ⅳ and V in comparison with those of control group. The weight and the growth index of the thymus were lower in high copper groups Ⅲ , IV and V than that in control group （P〈0.05 or P〈0.01）. The G0/G1 phase of cell cycle of the thymus was increased, and proliferating index （PI） was decreased in group Ⅳ and Ⅴ compared with those of control group（P〈0. 05 or P〈0. 01）. Percentage of apoptotic lymphocytes in the thymus was higher in high copper groups Ⅲ, Ⅵ and Ⅴ than that in control group （P〈0. 05 or P〈0. 01）. It was concluded that dietary copper in excess of 400 mg/kg inhibited the development of the thymus, caused pathological changes in the thymus and impaired the function of cellular immunity in ducklings.