Studies on the separation and mechanism of albumin synthesis in albumin-positive cells derived from Nagase analbuminemic rats (NAR).

点击翻译按钮获取中文摘要

Nagase analbuminemic rat (NAR) is characterized by very low serum albumin, hyperlipideamia, and normal rate of growth and propagation. however, a small number of albumin positive hepatocytes is distributed in the liver. We observed occurring modes of albumin positive cells in NAR due to aging, partial hepatectomy, and cirrhosis induced by CCl4 and neoplastic change after administration of 3'-Me-DAB. Those occurring modes had strong relation to regeneration of hepatocytes. In the aim to investigate albumin positive cells, we tried to separate these cells using percoll-density gradient centrifugation. Albumin positive cells relatively accumulated in the third fraction, however, these cells separated were not stable for applying the analytical method. Therefore, albumin positive cell line derived from NAR was required. After administration of 3'-Me- DAB, about 25 weeks later mixed type of hepatomas ( medullary, cystic and proliferated bile duct-like) were developed and 4 types of different cell lines were established until now. Established cell line showed several characteristics as follows: 1) epidermal-like shape in culture dish, 2) doubling time: 15-30 hr, 3) chromosome number: 60-120, 4) chromosome type: rat derived type. Immunohistochemical staining revealed AFP positive portion in cultured cells, but, albumin positive portion was hardly detected.Studies on the induction of albumin positive cells in cell lines have been continued by long-term culture and addition of hepatocyte stimulating factors.