Ge Z D, Chen M Z, Xu S Y
Institute of Clinical Pharmacology, Anhui Medical University, Hefei, China.
Zhongguo Yao Li Xue Bao. 1991 Jul;12(4):340-3.
[3H]Dihydroalprenolol ([3H]DHA) was used to label beta-adrenoceptors in intact lymphocytes isolated from rat spleen. The binding conditions were investigated by the methods of L9 (3(4)) orthogonal analysis, the results showed the optimum binding conditions were pH 7.7, 1 x 10(8) lymphocytes.ml-1 and 10 min at 25 degrees C for incubation. On these conditions the [3H]DHA binding to beta-adrenoceptors was rapid (T1/2 2 min) and readily reversed by propranolol 1 mmol.L-1 (T1/2 4 min). [3H]DHA saturation experiments indicated a single class of site with a KD of 7.2 +/- 2.2 nmol.L-1 and Bmax of 81 +/- 28 fmol/10(7) lymphocytes (n = 3). Computer analysis of competition experiments with isoproterenol and epinephrine revealed two classes of sites. One site had high affinity for the [3H]DHA and comprised 60 +/- 5% of the total number of sites, whereas the other site had a lower affinity. The affinity of the high affinity site was about 3 orders of magnitude higher than that of the lower affinity site.
[3H]二氢阿普洛尔（[3H]DHA）用于标记从大鼠脾脏分离的完整淋巴细胞中的β-肾上腺素能受体。采用L9(3(4))正交分析法研究结合条件，结果表明最佳结合条件为pH 7.7、1×10(8)个淋巴细胞/ml-1以及在25℃孵育10分钟。在此条件下，[3H]DHA与β-肾上腺素能受体的结合迅速（半衰期2分钟），且1 mmol.L-1普萘洛尔可使其迅速解离（半衰期4分钟）。[3H]DHA饱和实验表明存在一类单一的位点，其解离常数（KD）为7.2±2.2 nmol.L-1，最大结合容量（Bmax）为81±28 fmol/10(7)个淋巴细胞（n = 3）。对异丙肾上腺素和肾上腺素竞争实验的计算机分析显示存在两类位点。一类位点对[3H]DHA具有高亲和力，占总位点数的60±5%，而另一类位点亲和力较低。高亲和力位点的亲和力比低亲和力位点高约3个数量级。
