氯化镍对雏鸡盲肠扁桃体影响

Pathological changes of the cecal tonsils induced by dietary nickel chloride in chicken

本研究采用显微组织学、超微组织学以及末端脱氧核苷酸转移酶介导的dUTP缺口末端标记测定法(TUNEL)等方法,研究了日粮中高水平氯化镍(NiCl_2)对雏鸡盲肠扁桃体的影响。结果表明,NiCl_2处理组与对照组相比,盲肠扁桃体发育受到明显抑制;淋巴滤泡内弥漫排列的淋巴细胞明显减少。超微结构和TUNEL检测发现,900 mg/kg处理组盲肠扁桃体凋亡细胞增多,淋巴细胞线粒体肿胀或空泡化,同时也观察到淋巴细胞核膜扩张。结果表明,日粮中NiCl_2水平超过300 mg/kg时,可抑制盲肠扁桃体的生长,引起组织结构和细胞器的损伤,提示过量NiCl_2可使盲肠扁桃体正常发育和功能受损,从而导致雏鸡消化系统黏膜免疫功能降低。

This study aims to determine effects of dietary nickel chloride(NiCl2)on the development of cecal tonsil in broilers by the methods of light microscope(LM),transmission electron microscope(TEM)and TUNEL.Results showed that the development of cecal tonsils were significantly inhibited,and decreased lymphocytes with diffuse arrangement in lymphoid follicles were observed in the NiCl2 treated group when compared with the control group.By ultrastructure and TUNEL assays,more apoptotic cells were found in the 900 mg/kg group.The mitochondria of lymphocyte were swelled or vacuolated with degenerating cristae,the nuclear membrane of lymphocyte was expanded.In conclusion,dietary NiCl2 in excess of 300 mg/kg inhibited the growth of the cecal tonsil,and caused histological and ultrastructural damages,indicating that the normal development and function could be finally impaired by excessive NiCl2,which might cause depressed mucosal immune function of digestive system in broilers.