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Biomedical subjects

S Nagase

Publications and source records attributed to S Nagase.

At least 199 records · Page 11Linked to original sources
PubMed1983

Hypertriacylglycerolemia and adipose tissue lipoprotein lipase activity in the Nagase analbuminemic rat.

In Nagase analbuminemic rats, serum triacylglycerol levels were significantly elevated. This abnormality was accompanied by decreased adipose tissue fat stores, and both were more marked in female than in male rats. Parametrial adipose tissue lipoprotein lipase activity was determined in normally fed female rats. When expressed per mg protein, the activity in analbuminemic rats was only 35% of that in control rats. The activity in analbuminemic rats, however, could be increased as in control rats by refeeding starved animals with a fat-free and carbohydrate-rich diet, and the peak values recorded were the same with the two groups. Treatment of animals with streptozotocin lowered adipose tissue lipoprotein lipase activity in both groups to similar levels. These results suggest that hypertriacylglycerolemia associated with analbuminemia may be caused, at least in part, by altered hormonal control of adipose tissue lipoprotein lipase activity.

Adipose Tissue↗
PubMed1983

Agglutination assay of bladder cells by Concanavalin A proved the high susceptibility of analbuminemic rats to bladder carcinogens.

The susceptibility of analbuminemic rats, a mutant strain of Sprague-Dawley rats, to bladder carcinogens was examined by testing the agglutinability of isolated bladder epithelial cells by Concanavalin A (Con A). One-week treatment with 0.001% N-butyl-N-(4-hydroxybutyl)nitrosamine (BHBN) in the drinking water or 0.01% N-(4-(5-nitro-2-furyl)-2-thiazolyl)-formamide (FANFT), 0.01% and 0.1% 4-aminobiphenyl, 0.1% 4-nitrobiphenyl, 0.1% benzidine, 0.1% 2-napthylamine or 5% sodium saccharin in the diet clearly induced high agglutinability of bladder cells of male analbuminemic rats but not Sprague-Dawley rats. These results suggest that male analbuminemic rats are very susceptible to bladder carcinogens in general and therefore will be very useful in screening tests for bladder carcinogens.

2-Naphthylamine↗
PubMed1983

A seven-base-pair deletion in an intron of the albumin gene of analbuminemic rats.

Analbuminemic rats, which genetically lack serum albumin, have a mutation affecting albumin mRNA processing. Serum albumin genes were cloned from analbuminemic and normal parental Sprague-Dawley rats. Structural analyses of the two albumin genes showed that the gene from analbuminemic rats had a seven-base-pair deletion in an intron. The deletion extended from base 5 to base 11 from the 5' end of intron HI of the albumin gene. This deletion converted the sequence, G-T-A-G-G-T, which is normally located at the 5' end of intron HI, to G-T-A-G-C-G. RNA blot hybridization of analbuminemic and normal rat liver nuclear RNA using a DNA fragment containing the intron HI as a probe showed that this intron sequence persisted in albumin mRNA precursors of analbuminemic rats.

Animals↗
PubMed1983

Plasma clearance of sulfobromophthalein and its interaction with hepatic binding proteins in normal and analbuminemic rats: is plasma albumin essential for vectorial transport of organic anions in the liver?

To investigate a possible function of plasma albumin in the vectorial transport of organic anions by the liver, the plasma disappearance of sulfobromophthalein (BSP) and its interaction with plasma and liver cytosolic proteins were studied in normal rats and mutant Nagase analbuminemic rats (NAR). After intravenous administration of BSP, plasma BSP decreased rapidly in both NAR and control animals: plasma clearance values of BSP in NAR and controls were 12.45 and 7.40 ml/min per kg, respectively. Gel exclusion Sephadex G-100 chromatography of BSP with control rat serum revealed a protein peak in the void volume and another in the albumin fraction. BSP chromatographed exclusively with the albumin fraction; binding of BSP to plasma albumin occurred stoichiometrically. Similar studies with NAR serum revealed a single protein peak, in the void volume; a small amount of BSP chromatographed with this protein peak. The amount of BSP that chromatographed with NAR serum protein(s) was 8% of that with control rat serum albumin. Sephadex G-100 chromatography of BSP with control rat liver cytosol revealed four peaks of protein-bound BSP in fractions corresponding to the void volume (fraction X), albumin, glutathione S-transferases (fraction Y, Mr 45,000), and fraction Z (Mr 12,000); fraction Y was the major component of BSP binding. Gel chromatography of NAR liver cytosol with BSP revealed three BSP peaks, fractions X, Y, and Z; fraction X was the major component of BSP binding. Total BSP binding by 30 mg of hepatic cytosolic proteins was 4.5 nmol for controls and 10.4 nmol for NAR. Isoelectric focusing of liver cytosol revealed no quantitative or qualitative differences in glutathione S-transferase isozymes between control and mutant animals. Intravenously administered BSP (5 mumol/kg) rapidly appeared in bile as the free form and the glutathione conjugate in normal rats and NAR; 41% and 57% of injected BSP was excreted within 60 min in NAR and control rat bile, respectively. These results indicate that binding of BSP to plasma albumin is not indispensable to transhepatocyte transport of BSP in vivo.

Animals↗
PubMed1983

Tryptophan metabolism in analbuminemic rats.

Studies were made on tryptophan metabolism in Nagase analbuminemic rats (NAR), a mutant strain established from Sprague-Dawley rats that is characterized by lack of plasma albumin and hyperlipidemia. The total tryptophan concentration in NAR plasma is one fifth of normal, but the plasma free tryptophan concentration and liver and brain tryptophan levels are normal. Radioimmunoelectrophoresis showed that the tryptophan binding protein in NAR plasma is alpha 2-macroglobulin. The effect of oral tryptophan loading on plasma tryptophan and urinary excretion of tryptophan and its metabolites were examined. Differences between the values for NAR and normal rats were not significant except that the disappearance rate of tryptophan from NAR plasma was faster than in normal rats. The effects of several drugs that influence the concentration of non-esterified fatty acid (NEFA) or amino acids in the plasma of normal rats on NAR plasma tryptophan and NEFA concentrations and brain tryptophan metabolism were investigated. These drugs did not alter plasma NEFA and free tryptophan in NAR in the same direction as in normal rats. This difference may be caused by the difference of tryptophan binding proteins in the plasma of these two strains.

Amino Acids↗
PubMed1983

Plasma lipid concentrations and enzyme activities in Nagase analbuminemia rats (NAR).

Plasma lipid concentrations in NAR (Nagase Analbuminemia Rats) of 4 to 52 weeks old were examined. Plasma enzymes of NAR were also measured in relation to liver function. The concentrations of total lipid, total cholesterol, phospholipid and triglyceride tended to be increased in NAR, while that of non-esterified fatty acid (NEFA) was decreased. The lipid levels (except NEFA) were especially high in female adult NAR, and they were increased with aging. The effect of 17 beta-estradiol or testosterone administration on serum lipid concentrations was studied in gonadectomized NAR. Administration of 17 beta-estradiol to gonadectomized NAR increased lipid concentrations, while testosterone administration did not affect lipid levels. The effect of albumin injection on lipid concentrations in female NAR was also investigated. Albumin treatment to female NAR lowered serum lipid concentrations. Plasma glutamic oxaloacetic transaminase, glutamic pyruvic transaminase, lactate dehydrogenase and leucine aminopeptidase activities were higher in NAR than in normal rats. Plasma alkaline phosphatase and cholinesterase activities of NAR were similar to those of normal rats.

Age Factors↗
PubMed1983

Treatment and improvement of the breeding system of the albumin-deficient and jaundiced strain of rats.

The AJR (alb/alb, j/j) strain is semi-lethal and the rats die at about two weeks of age. Cross breeding with a pari of ACJ (alb/alb, j/+) is required for maintenance and production. We studied the treatment of AJRs for improvement of the breeding system. AJRs with jaundice on the skin at about 7 days of age were intraperitoneally administered 1 ml/rat of normal rat serum every few days and irradiated with visible light for 14 hours a day in an irradiation box. This treatment allowed us to obtain mature AJRs. The treatment was effective when applied for short periods of 1-4 weeks of age. The frequency of maturation of the treated AJRs was about 27% and the best mating combination was a female ACJ and male AJR. The treatment of AJRs, made the progeny test for the selection of ACJs for breeding pairs of ACJ X ACR unnecessary and increased the frequency of appearance of AJRs to 50%.

Animals↗
PubMed1983

Age-related changes in plasma proteins of analbuminemic rats.

A mutant strain, Nagase analbuminemia rats (NAR), was established from Sprague-Dawley rats. Age-related changes in plasma proteins of NAR were investigated to obtain information of their abnormalities of protein metabolism. The total protein concentration in the serum of NAR of various ages was almost the same as that of normal rats of the same age. The albumin level of NAR was less than 0.05 mg/ml at all ages examined. The concentrations of serum alpha 1-antitrypsin, alpha-X protein, alpha 2-macroglobulin, transferrin, ceruloplasmin, IgG, IgA and IgM were higher in NAR than in normal rats except for the perinatal stage, but alpha 1-acid glycoprotein level in NAR was normal. The serum transferrin and ceruloplasmin levels were especially high in female adult NAR. The plasma fibrinogen concentration was also increased in NAR. These findings indicate that the normal total serum protein level of NAR was maintained by increase in the globulin concentration.

Aging↗
PubMed1983

High incidence of renal tumors induced by N-dimethylnitrosamine in analbuminemic rats.

Analbuminemic rats were found to be highly susceptible to induction of renal tumors. Thirty-nine weeks after N-dimethylnitrosamine administration, the incidence of renal tumors and average weight of kidneys (including tumors) were 76.0% and 10.8 +/- 4.1 g in male analbuminemic rats, respectively, whereas they were 37.1% and 3.5 +/- 0.1 g, respectively, in normal male SD rats.

Animals↗
PubMed1982

Presence of albumin mRNA precursors in nuclei of analbuminemic rat liver lacking cytoplasmic albumin mRNA.

Analbuminemic rats, which lack serum albumin, were previously found to have no albumin mRNA in the cytoplasm of the liver. In the present study, the existence of nuclear albumin mRNA precursors in the liver of analbuminemic rats was examined by RNA X cDNA hybridization kinetics. Albumin mRNA precursors were present in the nuclei of analbuminemic rat liver at almost normal levels, despite the absence of albumin mRNA from the cytoplasm. Nuclear RNA of analbuminemic rat liver was subjected to electrophoresis on 1% agarose gel in parallel with nuclear RNA of normal rat liver. RNA was transferred from the gel to diazobenzyloxymethyl-paper and hybridized to cloned cDNA. Several bands of putative albumin mRNA precursors were obtained with nuclear RNA of analbuminemic rat liver and some of them were indistinguishable from those of normal rat liver. Nuclear RNA of analbuminemic rats was hybridized to 3'-end-labeled cloned cDNA under the conditions of RNA excess and then digested completely with S1 nuclease and subjected to electrophoresis on polyacrylamide gel. By this technique, nuclear RNA that could hybridized to cDNA was found to have the albumin mRNA sequence in at least the 3' half of the mRNa that was covered by cloned cDNA. For comparison of the structures of the albumin genes of analbuminemic and normal rats, DNAs from rat livers of both types were digested completely with EcoRI, HindIII, and Pst I; the fragments were separated by electrophoresis on 1% agarose gel, transferred to nitrocellulose paper, and hybridized to cloned cDNA. The intensities of the corresponding bands and the digestion patterns of the analbuminemic and normal rat genes were indistinguishable. From these data, it is concluded that analbuminemic rats have a unique type of mutation(s) affecting albumin mRNA maturation.

Animals↗
PubMed1982

A simple method for the determination of glucosamine and galactosamine using cellulose acetate electrophoresis.

A new electrophoretic method is presented for the determination of glucosamine and galactosamine. The technique is quite simple and rapid, it involves cellulose acetate electrophoresis in borate buffer (200 V, 15 min) and silver nitrate staining. Hexosamine samples of 0.36-1.80 micrograms were separated and stained within 30 min. This method was applied for the hexosamine analysis of glycosaminoglycans.

Animals↗
PubMed1982

Synthesis and secretion of plasma proteins by isolated hepatocytes of analbuminemic rats.

The synthesis and secretion of plasma proteins by isolated hepatocytes from the liver of Nagase analbuminemia rats (NAR) were investigated. NAR hepatocytes did not synthesize any albumin, but showed enhanced synthesis and secretion of several other plasma proteins, including transferrin, hemopexin, ceruloplasmin and fibrinogen. The lag period before the secretion of transferrin in NAR hepatocytes decreased. These findings indicate that the increased concentration of plasma globulins in NAR may be due to their enhanced synthesis and secretion in the liver.

Animals↗
PubMed1982

Perinatal changes of alpha-fetoprotein concentration in the serum and its synthesis in the liver of analbuminemic rats.

The profile of appearance of disappearance of alpha-fetoprotein (AFP) in the serum of analbuminemic rats, which have a genetically controlled lack of serum albumin, was studied. During the perinatal stage, AFP was present in the serum of analbuminemic rats, its concentration at birth being 10 mg/ml as in normal rats. In analbuminemic rats, the concentration of serum AFP remained at about 10 mg/ml during the first week after birth and then decreased rapidly during the next 2 weeks, becoming undetectable about 4 weeks after birth. In normal rats, the serum AFP concentration reached a maximum of 11.5 mg/ml at birth and then decreased sharply to an undetectable level within 4 weeks after birth, although a small rebound of AFP concentration was observed about 1 week after birth. AFP synthesis in analbuminemic and normal rats was examined by injecting [3H]leucine i.p. and then measuring the radioactivity incorporated into the acid-insoluble fraction and immunoprecipitable fraction using anti-AFP antiserum. In analbuminemic rats, synthesis of AFP amounted to 7.5% of the total protein synthesis at birth and was maintained at about 7% of the total for the first week after birth and then decreased to 2% at 2 weeks after birth. In normal rats, AFP synthesis also amounted to 7.5% of the total protein synthesis at birth but decreased to about 2% at 2 days after birth and then remained at a low level for about 2 weeks. In both normal and analbuminemic rats, AFP synthesis was undetectable at 4 weeks after birth. These data show that AFP synthesis is shutoff after birth irrespective of the serum albumin concentration during neonatal development.

Animals↗