７２０９９Ｅ是２１－氨基甾体类化合物之一，它缺乏已知的糖皮质激素（ＧＣ）及盐皮质激素的生理活性。本工作用放射配基结合法比较了Ｕ７２０９９Ｅ对于放射标记ＧＣ与大鼠脑胞液及突触质膜制备相结合的替代能力。结果表明：胞液与［３Ｈ］ＧＣ的结合不能被Ｕ７２０９９ｋ所替代，而突触质膜与［３Ｈ］ＧＣ的结合则可以被替代。后者其抑制常数（Ｋｉ）为３２．１６＋１．６５μｍｏｌ／Ｌ；这表明质膜上有与Ｕ７２０９９Ｅ相结合的位点，很可能即为糖皮质激素膜受体（ＧＣＭＲ）。由于Ｕ７２０９９Ｅ的Ｋｉ值与保护脑损伤所需的浓度相接近，这提示ＧＣＭＲ可能介导Ｕ７２０９９Ｅ的有益作用。 72099E is one of 21-amino steroid compounds that lacks the known glucocorticoid (GC) and mineralocorticoid physiologic activity. This work uses radioligand binding method to compare the substitution ability of U72099E for the combination of radiolabeled GC with rat brain cytosol and synaptic plasma membrane preparation. The results showed that the binding of cytosolic to [3H] GC could not be replaced by U72099k, but the binding of synaptophysin to [3H] GC could be replaced. The latter had a Ki value of 32.16 + 1.65 μmol / L, indicating that there is a site on the plasma membrane that binds to U72099E and is likely to be the glucocorticoid membrane receptor (GCMR). Since the Ki value of U72099E is close to the concentration required to protect brain damage, this suggests that GCMR may mediate the beneficial effects of U72099E.