To better understand the mechanism of phosphatidylcholine synthesis in the stomach, [3H] choline incorporation into phosphatidylcholine in response to agents which have been shown to induce phosphatidylcholine biosynthesis in other tissues was examined using isolated guinea pig gastric glands. Palmitate and 12-O-tetradecanoyl phorbol 13-acetate (TPA) which has been shown to activate protein kinase C directly, stimulated [3H] choline incorporation into phosphatidylcholine in gastric glands, by 189±12.9%, and 129±10.4% of control, respectively (n=4, p<0.01, p<0.05). On the other hand, dibutyryl cyclic AMP had no effect on the incorporation. When the glands were pulsed with [3H] choline followed by incubation in the presence of palmitate and TPA for 180min to see the effects of the agents on the limiting step of the phosphatidylcholine synthesis, phosphatidyl-[3H] choline was increasd to 167±7.5% and 142±7.5% of control respectively (n=4, p<0.01, p<0.05). In parallel to the increase in phosphatidylcholine synthesis, phosphoryl-[3H] choline in the glands incubated with palmitate and TPA was decreased as compared with control. These results suggest that palmitate or TPA may stimulate phosphatidylcholine biosynthesis through the activation of cytidylyltransferase in the stomach.
The response of glucose, insulin and glucagon to L-alanine tolerance test (0.5g/kg, intravenously, A.T.T.) was examined in dogs following hepatectomy. Before A.T.T., dogs were starved for 24 hours after antecedent carbohydrate-free diets. Under this condition, hepatic glycogen and blood glucose were 0.5±0.2mg/g liver and 85±11.9mg/dl, respectively. The marked response of blood glucose to alanine tolerance test was observed and the maximal increment above the basal level was 47±5.2mg/dl at 30 minutes after A.T.T. One week after 44% and 70% hepatectomy, the increments of glucose at 30 minutes after A.T.T. were 58% and 24% respectively, as compared with those before hepatectomy. These results suggest that the glucose response to alanine tolerance is usefull for an index of functional reserve of glucose production in the remnant liver after hepatectomy. The increments of blood glucose at 30 minutes after A.T.T. 1, 2, 3 and 4 weeks after 70% hepatectomy were 24.0, 21.8, 52.7 and 80% of that before hepatectomy respectively. The insulin response to alanine tolerance gave two peaks at 2.5min and 30min and the latter peak was dependent on the blood glucose response before and after hepatectomy. One or two weeks after 70% hepatectomy, the exaggerated glucagon response to alanine tolerance was observed. These results suggest that A.T.T. is not only an excellent index of functional reserve of hepatic gluconeogenesis, but also is an appropriate method for investigation of the relation between endogenous glucose production and endocrine pancreas.
We have developed a finger-piece method that can indicates an acculate concentration of ICG based on the two wavelength spectrophotometry. Seventy-eight subjects were evaluated by this new method. The ICG clearance curve obtained from ICG clearance meter showed a rapid increase 20 or 40 seconds after the bolus injection. The curve decreased gradually, and increased again at 60 or 70 seconds. Plasma disapperance rate (PDR) by this method (XK ICG) was calculated by the at least square method from 600 data obtained from 5 to 15 minutes after the injection. There was a significant correation between conventional PDR (KICG) and new method (XK ICG) also. We assume that this method have a possibility to discover new aspect of pharmakokinetics of ICG.
Alkaline and neutral elution techniques were applied to detect chemical carcinogens in biliary tract cancer using biliary tarct epithelial cells in culture. Since biliary tract epithelial cells actively grow in culture, DNA breaks induced by carcinogens in the [14C] thymidine-prelabeled DNA could be detected as radioactivities in the eluted fractions. Our study demonstrated that aflatoxin B1, 20-methylcholanthrene and dimethylnitrosamine induced DNA single-strand breaks in the biliary tract epithelial cells by the use of this system. Cultured biliary tract epithelial cells/alkaline and neutral elution offers a sensitive and organ-specific model for the detection of chemical carcinogens to the biliary tract epithelium.
The hamster gallbladders were investigated to clarify the morphological changes in the contracted and distended states. 1) The mucosal surface showed the highly convoluted folds in the contractd state, and the flat structure in distended state. 2) The hight and width of mucosal epithelial cells were changed in correspondence with the contracted and distended state of the gallbladder. 3) A subepithelial blood capillary formed a well developed network, and possessed many pores opening mainly toward the mucosal epithelial cell. Three-dimensional structure of blood capillary was closely related to the morphological changes of the mucosal fold. 4) A contraction of distention of muscle layer of the gallbladder produced concomitant widening or narrowing of the lymphatic vessel lumen. It is suggested that muscular contraction worked as a "pump" for the lymphatic flow. 5) Smooth muscle cells in the muscle layer had many cell-to-cell junctions, but few neuromuscular junctions. It seems that there is a complicated interaction between nervous and humoral control mechanisms.
Human pancreatic kallikrein (H. Panc. K.) was purified from human pancrea by serial liquid chromatographies. The final preparation had a specific activity of 9.2AU/A280 (AU: amidase unit for H-Pro-Phe-Arg-MCA) and its N-terminal sequence coincided with the reported sequence determined from cloned cDNA analysis. In HPLC (gel filtration), one symmetrical peak corresponding to a molecular weight of 48, 000 was obtained. In SDS-PAGE without 2-mercaptoethanol, one band corresponding to a molecular weight of 52, 000 was obtained. Protease inhibitor specificites of H. Panc. K. were the same as those of human urinary kallikrein (HUK) and hog pancreatic kallikrein (hog Panc. K.), while anti-HUK rabbit antibody inhibited the activities of H. Panc. K. and HUK, but not that of hog Panc. K.. From the analyis of affinity for concanavalin A and erythroaggulutinating phytohemagglutinin, the carbohydrate parts of H. Panc. K. are relatively rich in bi-(or multi-) antennary complex type sugar chains with bisecting G1cNAc compared with those of human salivary kallikrein and HUK. These findings will be a help to clarify the physiological and pathophysiological roles of H. Panc. K. in the pancreas and pancreatic diseases, especially in acute pancreatitis.
Ras genes (H-, K-, N-ras) are converted to active oncogenes by point mutations occuring in either colon 12, 13 or 61. We analyzed 19 pancreatic tumors (formalin fixed paraffin embedded tissue) of these codons by a method to directly sequence nucleotides around colons 12/13 and 61 of the three ras genes, using polymerase chain reaction and direct sequecing method. Of 19 pancreatic tumors, all 17 duct cell carcinomas involving 2 mucous producing pancreatic cancers had point mutations of the K-ras codon 12, but 2 islet cell tumors had no point mutation around codons 12, 13, 61 of the three ras genes. Extremely high incidence of ras gene mutation may be relevant to certain pathogenesis of pancreatic cancers.
Basal plasma cholecystokinin levels were measured by a bioassay using dispersed rat pancreatic acini in various digestive diseases and compared with corresponding values by CCK-8 specific radioimmunoassay. The mean basal level in healthy volunteers was 0.40±0.06pM. The basal level in liver cirrhosis was significantly elevated to 0.92±0.14pM. The patients with cholestasis, that is, primary biliary cirrhosis and obstructive jaundice due to choledocholithiasis, bile duct cancer or lymph node metastase, had markedly increased basal plasma CCK-8 like bioactivities from 1.88pM to more than 25pM. These CCK bioactivities were not correlative with CCK immunoreactivities. It was concluded not only that basal plasma CCK in patients with bile flow disturbance were truely increased, but also that interfering substances of the bioassay might appear in the plasma of these patients.