糖皮质激素受体阻断对大鼠实验性自身免疫性重症肌无力的影响

研究重症肌无力（ＭＧ）患者外周血白细胞糖皮质激素受体（ＧＲ）减少，而血浆皮质醇则在正常范围，探讨其与ＭＧ发病的关系。方法ＳＤ大鼠３２只，随机分成４组。实验组先以ＧＲ的竞争性拮抗剂米非司酮（ＲＵ３８４８６，ＲＵ４８６）阻断其ＧＲ，再以从人肌肉中粗提的乙酰胆碱受体（ｎＡＣｈＲ）进行免疫；实验对照组单用ｎＡＣｈＲ，试剂对照组只用ＲＵ４８６，而正常对照组仅用福氏佐剂。以临床症状、血清抗ｎＡＣｈＲ抗体（ｎＡＣｈＲ－ａｂ），重复刺激坐骨神经递减幅度为观察指标。结果实验组的临床症状和ｎＡＣｈＲ－ａｂ滴度升高及肌电图递减幅度均较明显，经ｔ检验分析，均与实验对照组有显著性差异（Ｐ＜０．０５），而试剂对照组和正常对照组均无ＭＧ的表现。结论ＧＲ被阻断后，对大鼠的实验性自身免疫性ＭＧ（ＥＡＭＧ）发病有易化作用。

Effect of blockage of glucocorticoid receptor on experimental autoimmune myasthenia gravis in rats

Objective Our previous clinical studies have shown that the glucocorticoid receptors (GR) of the leukocytes in peripheral blood of myasthenia gravis (MG) patients are lessened, while the plasma concentration of cortisol is normal. From these, we presume that there may be some relation between the lessening of GR and the onset of MG. Method Therefore, we used 32 Spraque Dauley(SD) rats and divided them into four groups at random. In the experimental group, after the GR blocked by RU 38 486(RU 486), the rats were immunized repeated with the crude extract of human muscle acetylcholine receptor (AChR). The experimental controls were only immuniced repeatedly with AChR. The reagent controls were only injected with RU 486, while the normal controls were injected only with the adjuvants. We observed the clinical symptoms of the rats, the titors of AChR Antibody (AChR ab) and the degrees of decremental responses to repeated stimulations of the sciatic nerves. Results Experimental rats had significantly more serious muscular weakness, higher titers of AChR ab, and more decremental response to repeated stimul on the sciatic nerves than these of the experimental controls. It has a remarkable difference by t test ( P <0.05). While both the reagent controls and the normal controls have no symptoms of MG. Conclusions It suggests that the lessening of GR play a facilitatory role to the onset of experimental autoimmune myasthenia gravis (EAMG).