Search PubMed⌕ Search

Biomedical subjects

S Fujii

Publications and source records attributed to S Fujii.

At least 955 records · Page 53Linked to original sources
PubMed1978

Cellular factors for stimulation of nucleosomal template activity for in vitro DNA synthesis.

Nucleosomes isolated from Yoshida sarcoma chromatin by micrococcal nuclease treatment were relatively inactive as templates for in vitro DNA synthesis. However, the template activity increased by trypsin digestion of nucleosomes or addition of heparin to the reaction mixture. This indicates that the nucleosomal template activity is masked. A crude extract of Yoshida sarcoma cells stimulated the nucleosomal template activity. The stimulatory factor was separated into three peaks by DEAE cellulose column chromatography. The same three peaks were observed in normal rat liver extract with much lower activities, but enhanced in regenerating liver. The factors seem to stimulate DNA synthesis by activating DNA template in nucleosomes without degrading histones or changing the primary structure of nucleosomal DNA.

Animals↗
PubMed1978

Studies on reduction of lipolysis in adipose tissue on freezing and thawing.

Adrenaline-induced lipolysis in fat cells was remarkably reduced when the cells were preincubated in a dry ice-aceton bath, but their adenylcyclase and lipase activities were not reduced. In the reconstructed lipid micelles which consisted of lipase-depleted lipid micelles and lipase-containing adipose tissue extract, adrenaline, theophylline and DBcAMP-induced lipolysis was not found when lipase-depleted lipid micelles were preincubated in a dry ice-aceton bath but was found when lipase was preincubated.

Adenylyl Cyclases↗
PubMed1978

Studies on the mechanism of action of ACTH on triglyceride synthesis in fat cells.

It was found that ACTH greatly reduced lipogenesis in fat cells in the presence of calcium ion, but not in the absence of calcium ion. Of the enzymes involved in triglyceride synthesis from fatty acid in lipid micelle membranes, only acyl-CoA synthetase was inhibited by calcium ion, the apparent Ki value of calcium ion being 4.2 X 10(-4) M. The Km values of the enzyme for palmitate and ATP were 2.0 X 10(-4) M and 2.5 X 10(-4) M, respectively and calcium ion caused non-competitive inhibition with both palmitate and ATP. The acyl-CoA synthetase activity of lipid micelle membranes was inhibited by treatment with phospholipase A or C, but not by treatment with phospholipase D. The mechanism of inhibition of triglyceride synthesis by ACTH is discussed on the basis of these results.

Adipose Tissue↗
PubMed1978

Inhibition of 7,12-dimethylbenz[alpha]anthracene-induced mammary tumorigenesis in rats by a synthetic protease inhibitor, N,N-dimethylamino-(p-(p'-guanidinobenzoyloxy)) benzilcarbonyloxyglycolate.

Oral administration of N,N-dimethylamino-(p(p'-guanidinobenzoyloxy))-benzilcarbonyloxy glycolate depressed induction of breast tumors in rats by a single intravenous injection of 7,12-dimethylbenz[alpha]anthracene. The latent period was delayed in the group fed on a diet supplemented with N,N-dimethylamino-(p(p'-guanidinobenzoyloxy))benzilcarbonyloxy glycolate. Administration of this compound for 40 days after 7,12-dimethylbenz[alpha]anthracene also significantly reduced the average weight of tumors per rat. These findings suggest that protease may play an important role in the process of mammary tumorigenesis.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1978

Tumorigenic action of streptozotocin on the pancreas and kidney in male Wistar rats.

Pancreatic islet cell tumors were induced in 38 of 44 male Wistar rats (86%), which survived 9 to 14 months following the various treatment schedules. A single i.v. injection of streptozotocin alone, 30, 40, 50, or 65 mg/kg of body weight produced adenomas of pancreatic islet cells in 8 of 9 (89%), 6 of 7 (86%), 2 of 4 (50%), and 1 of 2 rats (50%), respectively. The neoplasms were seen in all of the 8 rats given a single i.p. injection of picolinamide, 250 mg/kg of body weight, 15 min before a single i.v. injection of streptozotocin, 65 mg/kg of body weight. Among the 14 rats given a single i.p. injection of nicotinamide, 500 mg/kg of body weight, 15 min before a single i.v. injection of streptozotocin, 65 mg/kg of body weight, 13 rats (95%) developed pancreatic islet cell tumors. Renal tumors were seen in only 3 rats treated with streptozotocin and nicotinamide. None of rats used in this study developed hepatic tumors. This study demonstrates that steptozotocin, even in a dose of 30 mg/kg of body weight, has an exceedingly marked tumorigenic action on the rat pancreas, while it has little effect on the kidney and no effect on the liver.

Adenoma, Islet Cell↗
PubMed1977

Synthetic inhibitors of trypsin, plasmin, kallikrein, thrombin, C1r-, and C1 esterase.

p-Carbethoxyphenyl episol-guanidinocaproate and p-(p'-guanidinobenzoyloxy)-phenyl derivatives were prepared, and their inhibitory effects on trypsin, plasmin, plasma kallikrein, thrombin, C1r- and C1 esterase were examined. Among the various inhibitors tested, p-nitrophenyl p'-guanidinobenzoate, N,N-dimethylamino p-(p'-guanidinobenzoyloxy)-benzoyl glycolate and N,N-dimethylamino p-(p'-guanidinobenzoyloxy)-benzilcarbonyloxy glycolate were the most effective inhibitors of trypsin, plasmin, plasma kallikrien and thrombin, and they strongly inhibited the esterolytic activities of C1r- and C1 esterase.

Complement Activating Enzymes↗
PubMed1977

Purification and characterization of rat liver microsomal monoacylglycerol lipase in comparison to the other esterases.

Monoacylglycerol lipase was separated from triacylglycerol lipase and two kinds of esterase in the microsomes by heparin treatment and DEAE-cellulose column chromatography. Monoacylglycerol lipase was purified about 1200-fold by DEAE-cellulose, hydroxylapatite, SP-Sephadex and Sephadex G-100 column chromatography from rat liver whole homogenate. The purified enzyme showed a single protein band by sodium dodecyl sul fate gel electrophoresis. The molecular weight was calculated to be approx. 62 000 by gel filtration on Sephadex G-200 and sodium dodecyl sulfate gel electrophoresis. The enzyme had an isoelectric point of 6.80 and pH optimum of 8.5. The enzyme maximally hydrolyzed long chain monoacylglycerol such as monomyristoylglycerol and hydrolyzed 1(3)- and 2-monoacylglycerol at equal rates and showed a little hydrolytic activity on short chain triacylglycerol such as tributyrylglycerol, but did not hydrolyze long chain triacylglycerol. The enzyme had different Km and V in comparison with the esterase fro various short chain triacylglycerols and long chain monoacylglycerols. Moreover, monoacylglycerol lipase differed immunologically from two kinds of microsomal esterase. Diisopropyl fluorophosphate inhibited the enzyme activity completely.

Animals↗
PubMed1977

Purification and characterization of two types of esterase from rat liver microsomes.

It was found that about 90% of the triacylglycerol lipase activity of a rat liver microsomal fraction was released by heparin treatment. The residual microsomal fraction contained about 95% of the esterase activity but little triacylglycerol lipase activity. Two kinds of esterase (esterases I and II) were purified from this residual fraction by DEAE-cellulose chromatography, hydroxyapatite chromatography, isoelectric focusing and Sephadex G-200 chromatography. The final preparations of esterases I and II, which were puri fied 70-and 140-fold, respectively, gave single protein bands on polyacrylamide gel and sodium dodecyl sulfate-gel electrophoreses. The molecular weights of esterases I and II were calculated to be about 70 000 and 160 000 by gel filtration of Sephadex G-200. Their isoelectric points were 5.82 and 6.32. Both esterases completely hydrolyzed short-chain triacylglycerols, such as tributyrylglycerol, but did not hydrolyze long-chain triacylglycerols. They preferentially hydrolyzed medium-chain-length 1-monoacylglycerols, such as 1-monocaprylylglycerol. Esterase I differed immunologically from esterase II and it was found to constitute about 30% of the total esterase activity in the microsomal fraction; esterase II constituted 50--60%. These results show the existence of two isozymes of esterase in the microsomal fraction.

Animals↗