肉鸡腹水综合征患鸡右心组织钙沉积和Ca2+-ATPase活性变化

右心肥大衰竭是腹水综合征患鸡发病的重要环节之一,而心肌细胞内Ca^2＋浓度在调节心脏收缩和舒张功能及其生长方面都起着重要作用。本试验应用右心导管法测定AS患鸡右心压力变化情况,采用焦锑酸钾沉淀法、电镜酶细胞化学法研究AS患鸡右心组织Ca^2＋和钙泵（Ca^2＋-ATPase）活性变化及其精确定位。结果显示AS组肉鸡右心室舒张压极显著高于对照组（P〈0.01）,同时,右心室内压最大变化速率也极显著降低（P〈0.01）;对照组肉鸡右心组织偶见少量散在的Ca^2＋沉淀颗粒,低温诱发AS患鸡右心组织发生了明显的钙沉积;对照组肉鸡的右心组织Ca^2＋-ATPase以高电子密度颗粒分布于肌浆网、线粒体膜等处,AS患鸡心脏组织的Ca^2＋-ATPase的电子密度颗粒显著减少或缺失。本研究揭示,在低温条件下AS患鸡具有明显的右心舒张功能障碍,Ca^2＋浓度增高和Ca^2＋-ATPase功能抑制可能在其中起着重要作用。

The Change of Ca2+ and Ca2+ -ATPase of Right Ventricular Myocardium in Ascites Syndrome of Broiler Chickens

Right ventricular hypertrophy and failure is an important step in the development of ascites syndrome.Cytoplasmic calcium concentration is a major regulator of cardiac contractile function and various physiological processes in cardiac muscle cells.The purpose of this study was to measure the right ventricular pressure and investigate the precise ultrastructural location of Ca2 and Ca2 -ATPase in the right ventricular myocardium of chickens with ascites syndrome induced by low ambient temperature.The results showed that the right ventricular diastolic pressure(RVDP) of ascitic broilers was significantly higher than that of control broilers(P<0.01),and the maximum change ratio of right intraventricular pressure(RV dp/dtmax) of ascitic broilers was significantly lower than that of the controls(P<0.01).Extensively increased calcium deposits were observed in the right ventricular myocardium of ascitic broilers,whereas in the age-matched control broilers,calcium deposits were much less.The Ca2 -ATPase reactive grains were obviously found on the sarcoplasmic reticulum and mitochondrial membrane of the control right ventricular myocardium,but rarely observed in the ascitic broilers.The data suggested that in ascitic broilers there was the right ventricular diastolic dysfunction,in which the overload of intracellular calcium and inhibition of Ca2 -ATPase might be the important factors.