Vallet-Strouve C, Ferre F, Breuiller M
J Cell Physiol. 1984 Sep;120(3):391-6. doi: 10.1002/jcp.1041200318.
Cyclic AMP phosphodiesterase (PDE) activity was characterized in culture of ewe myometrial cells and its sensitivity to steroid hormones was tested. Cultured myometrial cells were maintained from the first to the 20th subculture in the presence of 2% of serum in a medium supplemented with 1 microM of insulin. It was found that myometrial cells possess a PDE activity with atypical kinetics. The nonlinear responses in Lineweaver-Burke plots suggest the presence of high- and low-affinity PDE activities. In cell culture, apparent Km values were similar to those obtained from the original myometrium. Vmax values increased with successive subcultures, revealing an increase in the capacity of the cells to degrade cAMP; in parallel, the growth rate decreased. The PDE specific activity in cultured myometrial cells was inhibited by estradiol or progesterone. When added together, no synergistic effect was obtained. The rate of inhibition for both steroids was constant during successive passages for both low- and high-affinity conditions. Results obtained in myometrial cell long-term culture were compatible with reports in other species in vivo. Considering the role of cAMP in the regulation of uterine functions, subcultured myometrial cells provided us a useful experimental system with which to study the cAMP metabolism process.
对母羊子宫肌层细胞培养物中的环磷酸腺苷磷酸二酯酶（PDE）活性进行了表征，并测试了其对类固醇激素的敏感性。在补充有1 microM胰岛素的培养基中，在2%血清存在的情况下，将培养的子宫肌层细胞从第1代维持到第20代传代培养。发现子宫肌层细胞具有非典型动力学的PDE活性。Lineweaver-Burke图中的非线性反应表明存在高亲和力和低亲和力的PDE活性。在细胞培养中，表观Km值与从原始子宫肌层获得的值相似。Vmax值随着连续传代而增加，表明细胞降解cAMP的能力增加；同时，生长速率下降。培养的子宫肌层细胞中的PDE比活性受到雌二醇或孕酮的抑制。当一起添加时，未获得协同效应。在连续传代过程中，两种类固醇在低亲和力和高亲和力条件下的抑制率都是恒定的。在子宫肌层细胞长期培养中获得的结果与其他物种体内的报道一致。考虑到cAMP在子宫功能调节中的作用，传代培养的子宫肌层细胞为我们提供了一个有用的实验系统，用于研究cAMP代谢过程。
