细胞钙超载与鸡柔嫩艾美耳球虫病损伤关系

为探讨鸡柔嫩艾美耳球虫（E．tenella）宿主细胞损伤与钙超载的关系，采用组织定量检测、Von Kossa钙染色、焦锑酸钾电镜细胞化学技术对使用和未使用钙离子阻断剂的E．tenella感染鸡盲肠组织的细胞沉积钙、ATP酶、磷脂酶A2（PLA2）、游离脂肪酸和盲肠上皮细胞游离Ca^2＋的含量与分布进行了动态测定和分析。结果表明：（1）鸡患柔嫩艾美耳球虫病过程中，宿主细胞内钙和游离Ca^2＋明显增多（P〈0．01），并随盲肠损伤加重而增加；（2）在发病过程中盲肠组织Na^＋-K^＋-ATP酶、Ca^2＋-Mg^2＋-ATP酶、总ATP酶活性均有不同程度的下降，在感染严重期显著低于不感染对照组（P〈0．01）；（3）钙超载盲肠组织的PLA2活性和游离脂肪酸含量明显升高（P〈0．01），表明钙超载是鸡柔嫩艾美耳球虫病的一个重要损伤机制；（4）硝苯地平可以阻止Ca^2＋内流，减少宿主细胞内游离Ca^2＋，减轻宿主细胞的损伤，在本病发生的早期盲肠损伤较轻时，对鸡有一定的保护力，但随着疾病的发展，其作用下降。

Relation of Calcium Overload and Damnification by Eimeria tenella in Chickens

In order to investigate the relationship between Ca~(2 ) overload and the injury of host cell of E.tenella infected chicken,the amount and the distribution of calcium,Na~ -K~ -ATPase,Ca~(2 )-Mg~(2 )-ATPase,the total ATPase,PLA_2,free fatty acid in caecum tissue as well as free Ca~(2 ) in caecum epithelium were examined.The results showed that in the process of E.tenella infection,the content of calcium and Ca~(2 ) increased obviously(P<0.01) with the severity of the disease.The activity of Na~ -K~ -ATPase,Ca~(2 )-Mg~(2 )-ATPase,the total ATPase in caecum tissue all decreased with the developing of the disease.In the serious phase of disease,the activity of these ATPases were significantly lower than that of the uninfected control group(P<0.01).Obviously elevated activity of PLA_2 and the content of free fatty acid demonstrated that overloaded calcium played an important part in the injury mechanism.Nifedipine could block the Ca~(2 ) internalization and decrease the Ca~(2 ) level in host cell,therefore could ease the injury and provide certain protection,but only effective in the initial phase of disease while the damage was slight and its function declined later.