Cammisa H M, Isom H C, Greene F E
Department of Pharmacology, Pennsylvania State University College of Medicine, Hershey 17033.
Endocrinology. 1988 Mar;122(3):991-6. doi: 10.1210/endo-122-3-991.
Plasma pseudocholinesterase (PsChe) activity was examined in adult female rat hepatocytes isolated by collagenase perfusion and maintained in a chemically defined medium supplemented with dimethyl sulfoxide. Time course studies on PsChe activity in cultured hepatocytes indicate that cells maintained in a chemically defined medium lacking human GH and 17 beta-estradiol (E2) exhibit a decrease in activity after the first 3 days in culture followed by a stabilization of PsChe activity for up to 15 days. GH (0.02, 0.2, and 2 micrograms/ml) increased PsChe activity in a dose-dependent manner. Addition of E2 (10(-5)-10(-7) M) alone to hepatocyte cultures did not cause an increase in PsChe activity. The increases produced by both the 2 micrograms/ml and 0.2 micrograms/ml GH doses plus E2 (10(-7) M) were significantly greater than controls and similar to the increase produced by GH alone. The ability of the hepatocytes to express PsChe activity was not dependent upon the continuous exposure of the cells to GH, since control cultures, maintained for 12 days in medium lacking GH, were able to express a high level of PsChe activity after the addition of GH (2 micrograms/ml) on day 12. This increase was observed in hepatocytes in culture for 30 days. These results indicate that GH plays a pivotal role in the regulation of PsChe activity in vitro, and that under the conditions used in this study, E2 does not influence the ability of hepatocytes in culture to express this enzyme.
通过胶原酶灌注分离并在添加二甲基亚砜的化学限定培养基中培养的成年雌性大鼠肝细胞，检测其血浆假性胆碱酯酶（PsChe）活性。对培养肝细胞中PsChe活性的时间进程研究表明，在缺乏人生长激素（GH）和17β-雌二醇（E2）的化学限定培养基中培养的细胞，在培养的前3天活性降低，随后PsChe活性稳定长达15天。GH（0.02、0.2和2微克/毫升）以剂量依赖的方式增加PsChe活性。单独向肝细胞培养物中添加E2（10^-5 - 10^-7 M）不会导致PsChe活性增加。2微克/毫升和0.2微克/毫升GH剂量加E2（10^-7 M）产生的增加显著大于对照组，且与单独GH产生的增加相似。肝细胞表达PsChe活性的能力不依赖于细胞持续暴露于GH，因为在缺乏GH的培养基中培养12天的对照培养物，在第12天添加GH（2微克/毫升）后能够表达高水平的PsChe活性。在培养30天的肝细胞中观察到了这种增加。这些结果表明，GH在体外PsChe活性的调节中起关键作用，并且在本研究使用的条件下，E2不影响培养的肝细胞表达该酶的能力。
