Schonberg M, Bilezikian J P, Apfelbaum M, Benn R C
J Cyclic Nucleotide Res. 1978 Feb;4(1):55-69.
The rat myogenic cell line, L8, contains a beta-adrenergic catecholamine-sensitive adenylate cyclase. Prior to cell fusion, and continuing thereafter, beta-adrenergic sites, as determined by the stereospecific binding of (125I)-hydroxybenqylpindolol, I1(125I)IHYP] increases from 470 to 2000 sites/cell. There is also an increase in adenylate cyclase (2-5 fold) and endogenous cAMP (5-30 fold) following stimulation by catecholamine. The dissociation constant (KD) of (125I)IHYP for unfused and fused cell-homogenates, as determined by estimation with Scatchard analysis, by direct determination at receptor concentrations well below the KD, or by association (4.6 X 10(8) M-1 min-1); and dissociation (0.028 min-1) kinetics; ranged from about 40 to 70 pM. The acquisition of beta-receptors prior to fusion in L8 cells may implicate this system in the regulation of myogenesis.
大鼠肌原细胞系L8含有一种对β-肾上腺素能儿茶酚胺敏感的腺苷酸环化酶。在细胞融合之前及之后，通过（125I）-羟基苄基吲哚洛尔[I1（125I）IHYP]的立体特异性结合所确定的β-肾上腺素能位点，从每个细胞470个增加到2000个。在儿茶酚胺刺激后，腺苷酸环化酶（增加2 - 5倍）和内源性环磷酸腺苷（增加5 - 30倍）也会增加。通过Scatchard分析估计、在远低于解离常数（KD）的受体浓度下直接测定或结合（4.6×10（8）M-1分钟-1）和解离（0.028分钟-1）动力学所确定的，（125I）IHYP对未融合和融合细胞匀浆的解离常数（KD）范围约为40至70皮摩尔。L8细胞在融合前获得β受体可能表明该系统参与了肌生成的调节。
