Turchi G, Carluccio M A, Oesch F, Gemperlein I, Glatt H R
Institute of Toxicology, University of Mainz, FRG.
Mutagenesis. 1987 Mar;2(2):127-35. doi: 10.1093/mutage/2.2.127.
Epithelial liver cells of the Chinese hamster (CHEL cells) were propagated in culture for 35 passages. At favourable cell densities, the population doubling time in normal medium, was 20 h. L-Tyrosine amino transferase activity was retained at a measurable level, but its enhancement by dexamethasone was detected solely in cells of early passages. Pyruvate kinase was strongly activated by fructose-1,6-biphosphate at low substrate concentrations. These enzymatic properties suggest that the CHEL cells are derived from a sub-population of parenchymal hepatocytes or from cells closely related to parenchymal hepatocytes. With a lag period of a few hours, CHEL cultures metabolized benzo[a]pyrene. In cell homogenates the various monooxygenase activities investigated were below the detection limits. However, other xenobiotic-metabolizing activities, such as cytochrome P-450 reductase, glutathione transferase and UDP-glucuronosyl-transferase were high, with levels comparable to those observed in freshly isolated rat parenchymal cells. Epoxide hydrolase activity was also detected, but was lower than in the liver. The CHEL cells were able to activate benzo[a]pyrene, 7,12-dimethylbenz[a]anthracene and aflatoxin B1 to mutagens, as shown in a co-culture assay with V79 cells, in which acquisition of resistance to 6-thioguanine was studied. At early passages, the CHEL cells had a near diploid set of chromosomes. Then, gradually the frequency of cells with slight changes in the number of chromosomes and the frequency of tetraploids were increased. During the observation period (up to passage 20) the modal number of chromosomes shifted from 22 to 23. No gross morphological changes in the cultures were noticed during the 20 passages.(ABSTRACT TRUNCATED AT 250 WORDS)
中国仓鼠的上皮肝细胞（CHEL细胞）在培养中传代35次。在适宜的细胞密度下，正常培养基中的群体倍增时间为20小时。L-酪氨酸氨基转移酶活性保持在可测量水平，但仅在早期传代细胞中检测到地塞米松对其的增强作用。丙酮酸激酶在低底物浓度下被1,6-二磷酸果糖强烈激活。这些酶学特性表明CHEL细胞来源于实质肝细胞亚群或与实质肝细胞密切相关的细胞。经过数小时的延迟期后，CHEL培养物代谢苯并[a]芘。在细胞匀浆中，所研究的各种单加氧酶活性低于检测限。然而，其他外源性物质代谢活性，如细胞色素P-450还原酶、谷胱甘肽转移酶和UDP-葡萄糖醛酸基转移酶活性较高，其水平与新鲜分离的大鼠实质细胞中观察到的水平相当。还检测到环氧化物水解酶活性，但低于肝脏中的活性。如在与V79细胞的共培养试验中所示，CHEL细胞能够将苯并[a]芘、7,12-二甲基苯并[a]蒽和黄曲霉毒素B1激活为诱变剂，该试验研究了对6-硫鸟嘌呤抗性的获得情况。在早期传代时，CHEL细胞具有近二倍体的染色体组。然后，染色体数量略有变化的细胞频率和四倍体细胞频率逐渐增加。在观察期（至第20代）内，染色体众数从22变为23。在20代培养过程中未注意到培养物有明显的形态变化。（摘要截短至250字）
