Colley A M, Cavanagh H D, Drake L A, Law M L
Curr Eye Res. 1985 Sep;4(9):941-50. doi: 10.3109/02713689509000001.
DNA and RNA polymerase activities in the purified nuclear fraction from cultured rabbit corneal epithelial cells were assayed over a range of substrate (labeled dTTP or UTP) concentrations using calf thymus DNA as template. Effects of carbamylcholine on polymerase activities were evaluated over a range of drug concentrations including those saturating muscarinic receptors. Carbamylcholine significantly (p less than 0.001) enhanced activity of both polymerases, both in nuclei incubated with the drug during assay and in nuclei from carbamylcholine-treated cells. Drug effects were blocked by atropine. Regression analysis of Hill plots for variation of polymerase activity with carbamylcholine concentration indicated half-maximal activity of both polymerases at approximately 1 microM carbamylcholine. Mechanisms by which carbamylcholine may alter polymerase activities are discussed in relation to effects of the drug on nuclear enzymes of cyclic nucleotide metabolism and on cyclic nucleotide-dependent protein phosphorylation.
以小牛胸腺DNA为模板，在一系列底物（标记的dTTP或UTP）浓度范围内，测定了培养的兔角膜上皮细胞纯化核组分中的DNA和RNA聚合酶活性。在一系列药物浓度（包括使毒蕈碱受体饱和的浓度）范围内，评估了氨甲酰胆碱对聚合酶活性的影响。氨甲酰胆碱在测定期间与药物一起孵育的细胞核以及来自氨甲酰胆碱处理细胞的细胞核中，均显著（p小于0.001）增强了两种聚合酶的活性。药物作用被阿托品阻断。对聚合酶活性随氨甲酰胆碱浓度变化的希尔图进行回归分析表明，在约1 microM氨甲酰胆碱时，两种聚合酶的活性达到半数最大值。结合该药物对环核苷酸代谢的核酶以及环核苷酸依赖性蛋白磷酸化的影响，讨论了氨甲酰胆碱可能改变聚合酶活性的机制。
