Induction ofApoptosis in the ImmatureMouse Testes by aMixture ofMelamine and CyanuricAcid

The toxicity of melamine has attracted much attention since the recent outbreaks of renal injury in pets and infants. Previous studies indicated that melamine by itself had low toxicity, whereas a mixture of melamine and cyanuric acid (M+CA) could cause serious renal damage. At present, most researches on the toxicity of M+CA are focused on the kidney. However, little is known about the adverse effects of this mixture on the reproductive system. In the present study, the toxicity of M+CA to testes was investigated. Immature male mice were orally dosed with 0, 0.6, 3, and 15 mg kg-1 d-1 of a 1:1 M+CA for 28 d. Pathological changes occurred in germ cells, such as loose arrangement, reduced numbers and karyopyknosis, indicating that this mixture was toxic to spermatogenesis. Compared with the control group, the TUNELpositive germ cells increased significantly and the ratio of Bcl-2 to Bax, total antioxidant capacity and superoxide dismutase activity decreased significantly in the 3 and 15 mg kg-1 d-1 M+CA treated group, while the activities of caspase-3, caspase- 8 and caspase-9 remained unchanged. The results suggest that M+CA can induce apoptosis in the mice testes. The downregulation of Bcl-2/Bax and oxidative stress may play a pivotal role in the induction of apoptosis by M+CA in mice testes.     

影响牛胚胎移植效果的主要因素分析

胚胎移植技术自创立以来,经过不断发展和完善,已成为现代畜牧业尤其是高价值低繁殖力畜种繁育中不可或缺的技术手段.但由于胚胎移植是一个系统工程,其移植效果受供受体的选择、超排效果、胚胎质量、供受体的同期性、操作技术、营养及饲养管理水平等诸多因素的影响,移植效果也参差不齐.本文就影响牛胚胎移植效果的主要因素进行简要分析,以期...     

大肠埃希菌感染对家兔圆小囊组织结构及VIP表达的影响

应用组织病理学、免疫组织化学等方法,探讨大肠埃希菌感染对实验兔圆小囊的组织病理学损伤及血管活性肠肽(VIP)在兔圆小囊组织内的分布。结果显示,与对照组相比,感染组圆小囊黏膜层出现了明显的病理性损伤,黏膜下层淋巴滤泡的长度极显著变短(P0.01)。免疫组织化学染色结果显示,感染组兔圆小囊组织中的VIP的表达显著高于对照组(P0.05)。上述结果表明,大肠埃希菌感染可引起兔圆小囊组织结构明显的病理损伤,并导致圆小囊组织中VIP的表达明显增多。