LaBrecque D R
Am J Physiol. 1982 Mar;242(3):G289-95. doi: 10.1152/ajpgi.1982.242.3.G289.
An extract of normal weanling or adult regenerating rat liver called hepatic stimulator substance (HSS) stimulates incorporation of tritiated thymidine ([3H]dThd) into liver DNA. In vivo, it is organ specific, species nonspecific, displays diurnal rhythm, and has a molecular weight of approximately 10,000-20,000. It has now been further characterized in vitro. HSS retained organ specificity, stimulating normal adult hepatocytes in primary culture, the HTC, PLC, and MH1C1 hepatoma cell lines, and the PRC rat liver cell line. It did not stimulate human or mouse lymphocytes, 3T3 mouse fibroblasts, Y1BS1 mouse adrenal cells, Chinese hamster ovary cells, rat hypernephroma cells, C6 rat glial cells, or L1210 mouse leukemic cells. More detailed studies of the response of HTC cells to HSS revealed a dose-dependent increase in [3H]dThd incorporation (up to 30-fold) with a response to as little as 140-ng purified extract/ml culture medium. Autoradiography confirmed that the thymidine was taken up by nuclear DNA. This represented a true stimulation of growth as shown by an almost twofold increase in cell number after 6 days of exposure to low doses of HSS.
一种从正常断奶或成年再生大鼠肝脏中提取的物质，称为肝刺激物质（HSS），它能刺激氚标记胸腺嘧啶核苷（[3H]dThd）掺入肝脏DNA。在体内，它具有器官特异性、物种非特异性，呈现昼夜节律，分子量约为10,000 - 20,000。现在已在体外对其进行了进一步的特性分析。HSS保留了器官特异性，能刺激原代培养的正常成年肝细胞、HTC、PLC和MH1C1肝癌细胞系以及PRC大鼠肝细胞系。它不刺激人或小鼠淋巴细胞、3T3小鼠成纤维细胞、Y1BS1小鼠肾上腺细胞、中国仓鼠卵巢细胞、大鼠肾上腺皮质瘤细胞、C6大鼠神经胶质细胞或L1210小鼠白血病细胞。对HTC细胞对HSS反应的更详细研究表明，[3H]dThd掺入量呈剂量依赖性增加（高达30倍），对低至140 ng纯化提取物/毫升培养基有反应。放射自显影证实胸腺嘧啶核苷被核DNA摄取。如在低剂量HSS作用6天后细胞数量几乎增加两倍所示，这代表了真正的生长刺激。
