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Biomedical subjects

Y Otsuka

Publications and source records attributed to Y Otsuka.

At least 163 records · Page 9Linked to original sources
PubMed1986

Purification and characterization of complement activating-acidic polysaccharide from the root of Lithospermum euchromum Royle.

An extraordinary potent anti-complementary substance was isolated from the root of Lithospermum euchromum Royle (Japanese name: Nan-shikon) which activates the complement system in vitro, and the active principle was shown to be acidic polysaccharide (LR-polysaccharide IIa). LR-polysaccharide IIa was purified by chromatographies on DEAE-Sepharose, Sephadex G-100, concanavalin A-Sepharose, Ricinus communis agglutinin conjugated Sepharose, Sepharose CL-6B and Sepharose CL-2B. LR-polysaccharide IIa was found to be composed of rhamnose, fucose, arabinose, xylose, mannose, galactose and glucose in the molar ratios of 2.0:2.5:3.4:2.8:5.6:9.6:14.4. The polysaccharide also contained 15% of galacturonic acid and 3.8% of protein. The methylation analysis of the polysaccharide showed that rhamnose, arabinofuranose, xylose, glucose and galactose are present as a part of the nonreducing terminal residues. The main chain and side chains are composed of ----3Glc1----,----3Gal1----,----6Man1----,----4Gal1, [corrected] and the branching points consist of (formula; see erratum) These results indicated that LR-polysaccharide IIa has a highly complicated structure. A marked consumption of C4 was observed after the incubation of the serum with LR-polysaccharide IIa in the presence of the Ca++ ion. The anti-complementary activity of LR-polysaccharide IIa was reduced partially in the absence of the Ca++ ion. After the incubation of the serum with LR-polysaccharide IIa in the absence of Ca++ ion, a cleavage of C3 in the serum was found to have occurred through immunoelectrophoresis as well as from the consumption of the complement when rabbit erythrocytes were used in the assay system. These results indicate that the mode of complement activation by LR-polysaccharide IIa is via both the alternative and classical pathways. Complement titer also decreased in guinea pigs upon i.p. injection of LR-polysaccharide IIa.

Animals↗
PubMed1986

Prostaglandins and sodium balance during the reversal of chronic two-kidney, one clip hypertension in rats.

To determine the role of endogenous prostaglandins and sodium balance in the maintenance of high blood pressure in chronic two-kidney, one clip hypertension in rats, we studied the effect of indomethacin infusion on the reversal of hypertension by unclipping. Indomethacin was infused after control measurements, and blood pressure was monitored continuously in conscious rats. Parallel control experiments and sham operations were also performed. Inhibition of prostaglandin synthesis did not affect the postoperative course of blood pressure after the unclipping operation despite the marked decrease of urinary prostaglandin E excretion. The decrease of blood pressure after unclipping was significantly correlated with plasma renin activity prior to unclipping. Sodium balance was not significantly different between the experimental groups. These data indicate no major participation of prostaglandins in the reversal of chronic two-kidney, one clip hypertension, and suggest that the renin angiotensin system participates, at least in part, in the maintenance of high blood pressure in this model of hypertension.

Animals↗
PubMed1986

The loss of endothelium-dependent vascular relaxation in hypertension.

We investigated endothelium-dependent relaxation in rat aortae, using three models of experimental hypertension: deoxycorticosterone and salt; one-kidney, one clip renovascular hypertension; and coarctation. Isolated aortae were contracted with phenylephrine, and relaxation was subsequently induced with acetylcholine or calcium ionophore A23187. Blood vessels denuded of endothelium did not relax in response to acetylcholine or A23187. Blood vessels from animals with high blood pressure had decreased relaxation responses to acetylcholine and A23187, and also to the endothelium-independent vasodilator sodium nitroprusside. Unlike acetylcholine and A23187, however, nitroprusside completely relaxed the blood vessels from the hypertensive animals, though the sensitivity to nitroprusside was much lower in these vessels. Subsequent reversal of hypertension caused a return of endothelium-dependent relaxation. Loss of endothelium-dependent relaxation occurs readily in the aortae with the development of hypertension; this phenomenon appears to be related to elevated pressure.

Acetylcholine↗
PubMed1986

Studies on polysaccharides from Angelica acutiloba. V. Molecular aggregation and anti-complementary activity of arabinogalactan from Angelica acutiloba.

Anti-complementary active arabinogalactan IIb-1 (AGIIb-1) and inactive arabinogalactan IIb-2 (AGIIb-2) were isolated from an extract of the root of Angelica acutiloba Kitagawa. AGIIb-1 mainly consisted of arabinose, galactose, rhamnose and galacturonic acid in a molar ratio of 2.2:1.0:0.3:0.4, and AGIIb-2 mainly consisted of arabinose, galactose, galacturonic acid, and glucuronic acid in a ratio of 1.0:1.0:0.08:0.1. AGIIb-1 was found to form molecular aggregates as the result of self-aggregation in water. The aggregated form was found in the void volume by gel filtration using Sepharose CL-2B in water. However, AGIIb-2 did not show this behavior. When the AGIIb-1 aggregate was applied to a gel filtration column in 8 M urea or NaCl solution, the position of the peak fraction shifted to a lower molecular weight region, and the molecular weight of AGIIb-1 decreased with the increase of NaCl concentration in the gel filtration. These results suggested that the molecular aggregation of AGIIb-1 was caused by hydrogen bonding and ionic interaction and was Ca2+ ion independent. The anti-complementary activity of AGIIb-1 was seen to be dependent upon the degree of molecular aggregation, and the AGIIb-1 aggregate in water showed the highest activity. The results of methylation analysis indicated that AGIIb-1 contained a large amount of 3,5- or 3,4-di-O-substituted arabinosyl residues whereas AGIIb-2 contained a large amount of 6-O-substituted galactopyranosyl residues.(ABSTRACT TRUNCATED AT 250 WORDS)

Carbohydrates↗
PubMed1985

Immunopotentiator separated from hot water extract of the seed of Benincasa cerifera Savi (Tohgashi).

The separation and properties of a new immuno-potentiator, Benincasa cerifera mitogen (BCM) fraction, were investigated. BCM fraction was separated from hot water extract of the seed of Benincasa cerifera Savi (Tohgashi) by gel filtration using Sepharose 4B. BCM fraction is a heteropolymer consisting of uronic acid, neutral sugars, protein, and phosphorus. The proliferation and differentiation of murine B cells were markedly stimulated by BCM fraction. The in vitro development of peritoneal macrophages into antitumor macrophages was also activated by the addition of BCM fraction to cultures. BCM fraction augmented the IgM and IgG antibody responses against sheep erythrocytes (SRBC) and the induction of delayed-type footpad reaction against SRBC. The antitumor activity of BCM fraction was observed in terms of prolongation of the survival period of mice bearing Meth A fibrosarcoma. After hydrolysis with 1% acetic acid at 100 degrees C for 4 h, marked mitogenic activity was found in a precipitate composed of 29% neutral sugars, 50% uronic acid, 1% protein, and 0.1% phosphorus. The precipitate did not contain detectable amino sugar. The possibility that the biological activities of BCM fraction may be due to contamination by bacterial lipopolysaccharide was ruled out on the basis of the results of chemical analysis and of marked mitogenicity noted in C3H/HeJ spleen cell cultures.

Acetates↗
PubMed1985

Studies on polysaccharides from Angelica acutiloba--IV. Characterization of an anti-complementary arabinogalactan from the roots of Angelica acutiloba Kitagawa.

An anti-complementary polysaccharide, AR-arabinogalactan, was isolated from the roots of Angelica acutiloba Kitagawa (Japanese name = Yamato-Tohki), and purified by chromatography on DEAE-Sephadex A-50, Sephadex G-100, Sepharose CL-2B and concanavalin A-Sepharose. AR-arabinogalactan was composed of arabinose and galactose in a molar ratio of 1.2:1.0 and a small amount of galacturonic acid. The results of methylation and exo-alpha-L-arabinofuranosidase treatment showed that the polysaccharide was a branched arabinogalactan containing a backbone involving galactopyranosyl (1----6) linkages. Most of the arabinose was present as an alpha-L-furanosyl residue in the non-reducing terminals and side chains. The (1----3)-linked galactopyranosyl residue might be linked to the arabinosyl side chains. alpha-L-arabinofuranosidase digestion did not destroy the anti-complementary activity of the polysaccharide. After incubation of the serum with AR-arabinogalactan in the absence of Ca2+ ions, a cleavage of C3 in the serum was detected by immunoelectrophoresis as well as from the consumption of complement when rabbit erythrocytes were used in the assay system. A marked consumption of C4 was also observed to have occurred when serum was incubated with AR-arabinogalactan in the presence of Ca2+ ions. Collectively considered these results indicate that the mode of complement activation by AR-arabinogalactan is via both the alternative and the classical pathway.

Arabinose↗
PubMed1985

Lymphocyte activation by a polysaccharide fraction separated from hot water extracts of Angelica acutiloba Kitagawa.

The action of a polysaccharide fraction obtained from hot water extracts of Angelica acutiloba Kitagawa, termed as Angelica immunostimulating polysaccharide (AIP) fraction, on murine lymphocytes participating in antibody responses was investigated. When AIP fraction was injected concomitantly into mice immunized with antigens, immunoglobulin M (IgM) and IgG antibody responses against sheep erythrocytes (SRBC) increased significantly, but IgM response against T-independent antigens such as trinitrophenylated lipopolysaccharide (TNP-LPS) and TNP-Ficoll did not augment. Murine B lymphocytes were polyclonally activated in vitro and in vivo by AIP fraction to differentiate into antibody-forming cells as functionally matured cells. The differentiation of B lymphocytes to an intermediate stage capable of responding to helper T lymphocytes was also stimulated by the administration of AIP fraction into CDF1 and C3H/HeJ mice. A concomitant injection of AIP fraction with SRBC for carrier priming resulted in the increment of anti-TNP IgM antibody response in cultured reconstituted with unprimed B and SRBC-primed T lymphocytes, indicating that AIP fraction can stimulate T lymphocytes.

Animals↗
PubMed1984

Immunoglobulin classes of anti-Sendai virus antibody detected by ELISA in infected nude mouse serum.

Sendai virus-infected nude mouse sera obtained on the seventh day after infection or later, in which anti-Sendai virus antibodies were undetectable by hemagglutination-inhibition and neutralization tests, were found to be reactive with the virus antigen by ELISA using horseradish peroxidase-conjugated anti-mouse IgG rabbit IgG. The reactivity was blocked by rabbit anti-Sendai virus antiserum and was not observed against influenza virus which served as a control antigen. Anti-Sendai virus antibody activity of fractions from Sephadex G-200 gel filtration was detected in the IgM fraction when anti-mouse mu chain-specific antiserum was used and in both IgG and IgM fractions when heavy and light chain-specific anti-mouse IgG serum was employed in ELISA. ELISA of the fractions from protein A-Sepharose affinity chromatography of Sendai virus-infected nude mouse sera showed that the eluates at pH 6.0 and pH 3.5 contained IgG1 and IgG2b anti-Sendai virus anti-bodies, respectively, and that the eluate at pH 4.5 contained both IgG2a and IgG3 antibodies.

Animals↗