摘要
本实验研究了氢化可的松（Ｆ）对原代培养大鼠肝细胞酪氨酸转氨酶（ＴＡＴ）活性诱导的量效关系及糖皮质激素（ＧＣ）对大鼠肝胞液高、低亲和力ＧＣ受体（ＧＲ_Ｈ、ＧＲ_Ｌ）的调节。结果表明：Ｆ浓度在１～１０ｎｍｏｌ／Ｌ时，量效关系呈饱和趋势，超过１０ｎｍｏｌ／Ｌ以上直到１０μｍｏｌ／Ｌ，ＴＡＴ活性又不断上升。这效应可被ＧＲ_Ｈ的竞争性拮抗剂ＲＵ４８６完全阻断，提示ＧＲ_Ｌ能介导大剂量Ｆ对ＴＡＴ活性的诱导。将大鼠血浆ＧＣ浓度维持在１０^（－６）ｍｏｌ／Ｌ以上３ｄ，肝胞液ＧＲ_Ｈ的结合容量（Ｒ０）于注射Ｆ后１ｈ已明显减少，并维持于低水平，ＧＲ_Ｌ的Ｒ０在注射后１、２４、４８ｈ升高，说明ＧＣ对ＧＲ_Ｈ存在反向调节，但对ＧＲ_Ｌ却是正向调节。讨论了上述变化的病理生理及临床意义。
in this report we studied the relationship between hydrocortisone(F)concentration and its inductive effect on tyrosine aminotransferase(TAT)activity in primary cultures of rat hepatocytes,and regulation of high-and low-affinity glucocorticoid receptors(GR_H and GR_L in rat liver by glucocorticoids(GC).When F concentrations were 1～10 nmol/L,the dose response relationship showed a tendency to saturation.TAT activity was much higher when F concentration was between.10nmol/L and 10μmol/L,and the induction of TAT was completely inhibited by RU486,a competitive antagonist of RG_H and GR_L when F concentration was 10μmol/L. These results indicated that induction of TAT by high F concentration was mediated by GR_L Concentration of GC in plasma remained over 10￣(-6)mol/L for 3 d by subcutaneous injection of F in polyvinyl alcohol into the rats.The binding capacity(R0) of GR_H decreased significantly 1h after injection and remained at a low level.while R0 of GR_L increased at 1h,24h,48h after injection.It may be concluded that GC could down-regulate GR_H and up-regulate GR_L.The pathophysiological and clinical significance of these results is also discussed.
出处
《第二军医大学学报》
CAS
CSCD
北大核心
1994年第5期412-416,共5页
Academic Journal of Second Military Medical University
关键词
糖皮质激素
肝
酪氨酸转氨酶
受体
glucocorticoids
liver
tyrosine aminotransferase
glucocorticoid receptor
receptor regulation
rats
