摘要
应用Scatchard分析、Pseudoscatchard分析和置换曲线分析,发现大鼠肝胞液存在两类糖皮质激素(GC)结合位点:高亲和力结合位点(HAGS)和低亲和力结合位点(LAGS)。Pseudoscatchard分析得LAGSKd值为4.1±1.4μmol/L(n=4)。HAGS在0～4℃的自然失活速度比LAGS快,用DEAE-纤维素柱层析未能把两者区分开。HAGS的结合参数及甾体特异性与文献报道的经典GC受体相同。LAGS与[~3H]曲安缩酮的结合能被曲安缩酮、RU486、RU26988竞争性抑制,醛固酮、孕酮、雌二醇、睾丸酮则无抑制作用,说明LAGS与GC的结合具有特异性。LAGS与GC效应的关系尚需进一步研究。
Scatchard, pseudoscatchard and competitive analyses showed that there were two glucocorticoid (GC) binding sites in rat hepatic cytosol: high-affinity glucocorticoid binding sites (HAGS) and low-affinity glucocorticoid binding sites (LAGS). Pseudoscatchard analysis showed the dissociation constant (Kd) of LAGS was 4.1+1.4umol/L (n=4). The inactivation of LAGS in vitro was slower' than that of HAGS. LAGS and HAGS could not be separated by DEAE-cellulose chfomatography. HAGS were saturable and had steroid specificity for glucocorticoid just as the classic glucocorticoid receptor. Triamcinolone acetonide, RU486 and RU26988 competed equally well to LAGS while aldosterone, progesterone, estradiol and testosterone did not compete with LAGS. These results suggest that LAGS have steroid specificity for glucocorticoids. The biological actions of LAGS await fur ther study.
出处
《第二军医大学学报》
CAS
CSCD
北大核心
1991年第3期225-229,共5页
Academic Journal of Second Military Medical University
关键词
糖皮质激素
结合位点
亲和力
肝
glucocorticoids
binding sites
affinity
liver
