Sharma R K, McLaughlin C A, Pitot H C
Cancer Lett. 1975 Nov;1(2):61-7. doi: 10.1016/s0304-3835(75)95295-7.
The studies are presented which demonstrate that smooth endoplasmic membrane of normal liver has a single apparent binding site for cAMP with a KD of 0.6 X 10(-8) M. In contrast to this, however, cyclic AMP binding to the intracellular membrane of hepatoma 7800 exhibit two binding sites; the binding constant of one site on the tumor membrane is comparable to that of the normal liver whereas the value of the second intrinsic association constant differ by a factor of 10. It is suggested that there may be an association between abnormal cyclic nucleotide metabolism and the intracellular membrane modulation of the expression of genetic information in normal and neoplastic cells.
这些研究表明，正常肝脏的光滑内质膜对环磷酸腺苷（cAMP）有一个明显的结合位点，解离常数（KD）为0.6×10⁻⁸M。然而，与此形成对比的是，环磷酸腺苷与肝癌7800细胞内膜的结合表现出两个结合位点；肿瘤膜上一个位点的结合常数与正常肝脏的相当，而第二个内在缔合常数的值相差10倍。有人提出，在正常细胞和肿瘤细胞中，异常的环核苷酸代谢与遗传信息表达的细胞内膜调节之间可能存在关联。
