Junta Nakamura

HIGH LEVEL OF CA19-9, CA50, AND CEA-PRODUCIBLE HUMAN CHOLANGIOCARCINOMA CELL LINE CHANGES IN THE SECRETION RATIOS IN VITRO OR IN VIVO

SummaryThe ascites of a 78-yr-old Japanese woman with cholangiocarcinoma was used for a primary culture. An established new cell line (designated TK from the Japanese description of cholangiocarcinoma; Tankan-gann) showed conspicuous tumor marker production. A high level of circulating serum tumor markers; carbohydrate antigen (CA) 19-9, 32,000 U/ml; CA50, 6900 U/ml; and carcinoembryonic antigen (CEA), 300 ng/ml (on an average from 106 cells/ml for 3 d culture) were detected in the tissue culture supernatant. With an inoculum of 2×107 TK cells, nude mice progressively developed tumors. The histological features of the tumors forming in nude mice showed well-differentiated adenocarcinoma. Within the tumor mass, large amounts of extra cellular fluid retained approximately 590,000 U/ml of CA19-9, 200,000 U/ml of CA50, and 2000 ng/ml of CEA. Alpha-feto-protein was undetectable in the TK culture supernatant. There are few cholangiocarcinoma cell lines producing stable human tumor markers. Newly established TK cells derived from cholangiocarcinoma showed a stable production of serum tumor markers in vivo and in vitro. The changes in the tumor marker secretion ratios were shown to be dependent upon type of tumor cells, i.e., whether they are in vitro or in vivo. These features make TK cells a valuable tool for studying tumor markers.

Fluctuation of pancreatic peptide hormones in total-hepatectomy model in the rat.

A single-stage total-hepatectomy model in the rat is described. This model was successful in simulating the anhepatic phase for at least 4 h, with continuous intravenous glucose infusion. Advantages of the technique used for total hepatectomy in this study include ease of production, and resolution of problems encountered in previous models such as embolism and high postoperative mortality. This model was employed to observe fluctuation of pancreatic peptide hormones and glucose clearance during the anhepatic phase. Plasma insulin levels in portal blood did not vary for 120 min after removal of the liver. However, transient glucagon hypersecretion and depression in reactive secretion of somatostatin were observed during the anhepatic phase. These observations led to the following conclusions: (1) the liver seems to play an important role in regulating correlations between pancreatic peptide hormones by being part of a feedback system, and (2) hypersecretion of glucagon in the early anhepatic phase may be the initial signal for liver regeneration in the totally hepatectomized rat.