烧伤血清对大鼠腹腔巨噬细胞内游离钙浓度及其产生NO的影响

The effect of postburn serum on free intracellular calcium concentration and production of nitric oxide in macrophages

目的：观察烧伤血清对分离的大鼠腹腔巨噬细胞内游离钙离子浓度（［Ｃａ２＋］ｉ）和产生ＮＯ的影响。方法：收集腹腔巨噬细胞，用Ｆｕｒａ－２／ＡＭ作为细胞内游离钙离子指示剂测定［Ｃａ２＋］ｉ，用烧伤血清刺激体外的腹腔巨噬细胞即刻进行［Ｃａ２＋］ｉ的测定；用同浓度的烧伤血清刺激培养的腹腔巨噬细胞，测定上清ＮＯ稳定的代谢产物［ＮＯ２－＋ＮＯ３－］的浓度。结果：烧伤血清能显著地促进巨噬细胞［Ｃａ２＋］ｉ的增高，以烧伤后６ｈ血清的作用最为明显，可达正常对照组的９倍，维拉帕米可部分抑制其作用。烧伤血清对腹腔巨噬细胞ＮＯ的产生有明显的抑制作用，也以６ｈ烧伤血清为最明显。结论：烧伤血清能显著地升高腹腔巨噬细胞［Ｃａ２＋］ｉ，而ＮＯ的产生被明显地抑制。细胞内钙超载和ＮＯ产生减少可能是烧伤后早期巨噬细胞免疫功能损伤主要因素之一。

Objective: To test the changes of [Ca^(2+)]i and production of NO of peritoneal macrophages following stimulation of postburn serum. Methods: Peritoneal macrophages were isolated from SD rats. The cells were loaded with the Ca^(2+)sensitive fluorescent dye Fura2/AM and stimulated with postburn serum. The [ Ca^(2+)]i were measured by fluorescent cytometry and production of NO was determined by Griess dye method. Results: Postburn serum significantly increased the [Ca^(2+)]i of peritoneal macrophages as compared with normal control group(P<0.01). After pretreatment of verapamil, the effect of 6 h BS was partly inhibited, but [ Ca^(2+)]i was still higher than that of control group. The production of NO was decreased significantly after stimulated with all kinds of BS. Conclusion: Following the stimulation of postburn serum, macrophages exhibited increasing in [ Ca^(2+)]i and decreasing in production of NO. The calcium overload and the lower production of NO of the macrophages may be the important factors in burnmediated immunosuppresion. 