败血症大鼠心肌核被膜和肌浆网ryanodine受体的变化

为观察败血症时心肌肌浆网（ＳＲ）和核被膜（ＮＥ）的ｒｙａｎｏｄｉｎｅ受体的变化,采用结扎及穿刺盲肠（ＣＬＰ）制作败血症动物模型,用密度梯度离心分离ＳＲ和ＮＥ,用放射配体结合法研究ｒｙａｎｏｄｉｎｅ受体的特征。结果表明,大鼠早期败血症（ＣＬＰ后９ｈ）时,ＳＲ的ｒｙａｎｏｄｉｎｅ受体的最大结合（Ｂｍａｘ）增加２３％,ＮＥ的ｒｙａｎｏｄｉｎｅ受体的Ｂｍａｘ则增加１倍,二者比值降低３９％（Ｐ＜００１）;在晚期败血症（ＣＬＰ后１８ｈ）时,ＳＲｒｙａｎｏｄｉｎｅ受体的Ｂｍａｘ降低了３８％,ＮＥ的ｒｙａｎｏｄｉｎｅ受体的Ｂｍａｘ增加１６倍,二者比值降低７６％;ＳＲ和ＮＥｒｙａｎｏｄｉｎｅ受体的离解常数无显著改变。败血症时,ＳＲｒｙａｎｏｄｉｎｅ受体早期上调,晚期下调,而ＮＥｒｙａｎｏｄｉｎｅ受体均上调,这些变化可能与休克时相有关。

Alteration of ryanodine receptors in cardiac sarcoplasmic reticulum and nuclear envelope of rats during sepsis

To investigate changes of ryanodine receptors in the sarcoplasmic reticulum (SR) and the nuclear envelope (NE) of rat cardiac myocytes during sepsis induced by cecal ligation and puncture (CLP), myocardial SR and NE were fractionated with density gradient centrifugation and the characteristic of ryanodine receptor was assayed with a method of radioreceptor binding assay. The result showed that Bmax of ryanodine receptors in cardiac SR was increased by 23% during early sepsis (9 h after CLP), but decreased by 38% during late sepsis (18 h after CLP). Bmax of ryanodine receptors in cardiac NE, on the other hand, was increased by 100% and 160% during early and late sepsis respectively. Kd of ryanodine binding to SR and NE remained unchanged during sepsis. These results demonstrated up-regulation of ryanodine receptors in SR occurred during early sepsis and down-regulation of these receptors in SR occurred during late sepsis, while up-regulation of ryanodine receptors in NE occurred during both the early and the late sepsis.