Cortinovis C, Mayer D, Bouscarel B, Paris H, Murat J C
Gen Pharmacol. 1985;16(3):259-63. doi: 10.1016/0306-3623(85)90079-5.
The presence of specific binding sites for tritiated CGP-12177, a beta-adrenergic antagonist, was investigated in the preneoplastic-like C1I cell-line and in Morris hepatoma MH3924 cells. It was found that C1I cells possess beta-adrenoceptors with the following characteristics: KD = 1.58 +/- 0.56 nM and Bmax = 4.41 +/- 0.88 fmol/10(6) cells. No specific binding sites could be found on MH3924 cells. Stimulation of the C1I cells beta-adrenoceptors by isoprenaline, salbutamol, adrenaline and noradrenaline induced cyclic AMP accumulation. Noradrenaline was, however, a hundred times less efficient than adrenaline, as is the case in normal rat hepatocytes. The order of potency of beta-antagonists either to displace the bound radioligand or to counteract isoprenaline induced cyclic AMP accumulation (IPS-339 greater than propranolol much greater than atenolol) indicates that the adrenoceptors present on the C1I cells are of the beta 2-subtype.
在类癌前C1I细胞系和莫里斯肝癌MH3924细胞中研究了β-肾上腺素能拮抗剂氚标记的CGP-12177特异性结合位点的存在情况。结果发现，C1I细胞具有以下特性的β-肾上腺素受体：解离常数（KD）=1.58±0.56纳摩尔，最大结合容量（Bmax）=4.41±0.88飞摩尔/10⁶个细胞。在MH3924细胞上未发现特异性结合位点。异丙肾上腺素、沙丁胺醇、肾上腺素和去甲肾上腺素对C1I细胞β-肾上腺素受体的刺激可诱导环磷酸腺苷（cAMP）积累。然而，去甲肾上腺素的效能比肾上腺素低100倍，正常大鼠肝细胞中也是如此。β-拮抗剂取代结合的放射性配体或对抗异丙肾上腺素诱导的cAMP积累的效能顺序（IPS-339＞普萘洛尔＞阿替洛尔）表明，C1I细胞上存在的肾上腺素受体为β₂亚型。
