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Biomedical subjects

H Matsuda

Publications and source records attributed to H Matsuda.

At least 757 records · Page 42Linked to original sources
PubMed1996

Endothelins contract guinea-pig pulmonary artery and enhance its adrenergic response via ET(A) receptors.

1. This study has pharmacologically characterized endothelin (ET) receptor subtype(s) mediating contraction and enhancement of adrenergic contraction in guinea-pig pulmonary artery. Isometric tension of the isolated endothelium-denuded ring preparations was measured in the presence of indomethacin (10(-5) mol/L) and N(G)-nitro-L-arginine methyl ester (L-NAME; 3 x 10(4) mol/L) to exclude a mechanism via endothelium, cyclo-oxygenase-generated eicosanoids and nitric oxide. 2. In the additional presence of tetrodotoxin (TTX; 3 x 10(-7) mol/L), ET-1 (10(-11)-10(-7) mol/L) concentration-dependently contracted the preparations. The rank order of potency to contract the preparations among ET receptor agonists was ET-1, sarafotoxin (STX)6b > ET-3 > IRL 1620, STX 6c. BQ-123 (7 x 10(-7)-7 x 10(-6) mol/L) concentrations-dependently shifted the concentration-contraction curve for ET-1 to the right in a parallel manner. Pretreatment with STX 6c (3 x 10(-7) mol/L for 30 min) did not significantly desensitize contractions to ET-1, ET-3 or IRL 1620 (P > 0.05; t-test, 10 d.f). 3. ET-1 (10(-10)-10(-9) mol/L) and STX 6b (10(-9)-10(-8) mol/L) significantly enhanced the electrical field stimulation-induced contraction in a BQ-123-sensitive manner (P < 0.05: t-test, 24-38 d.f), while ET-3 (10(-11)-10(-8) mol/L) and STX 6c (10(-11)-10(-7) mol/L) did not affect contractions. ET-1 (10(-11) mol/L) significantly enhanced contractions to exogenous noradrenaline in the presence of TTX (3 x 10(-7) mol/L) (P < 0.05; t-test, 16 d.f.). 4. These data indicate that the BQ-123-sensitive ET(A) receptor mediates both contraction and enhancement of adrenergic contractions in the guinea-pig pulmonary artery.

Animals↗
PubMed1996

No association between c-fos gene polymorphisms and sporadic Alzheimer's disease.

Although ApoE epsilon 4 is a major risk factor for sporadic Alzheimer's disease (AD), 20-30% of sporadic AD patients do not have this allele. This indicates that other risk factors are involved in the pathogenesis of sporadic AD. Studies of the genetic association between AD and polymorphisms in the c-fos gene, a candidate gene for AD, were conducted. The polymorphisms of DsaI in exon 2 and Sau3 AI in intron 2 were examined in 89 patients diagnosed as sporadic cases of probable AD clinically and radiologically according to the NINCDS-ADRDA criteria. This was also undertaken in 96 controls. There was no significant difference between the groups in allele frequencies or genotype counts. Although c-fos gene as a locus conferring susceptibility to sporadic AD cannot be ruled out, these data could not support the hypothesis that a c-fos allele should be another risk factor for sporadic AD.

Aged↗
PubMed1996

Alterations of p16/CDKN2, p53 and ras genes in oral squamous cell carcinomas and premalignant lesions.

Exons 1-3 of the p16/CDKN2 gene, exons 4-9 of the p53 gene and exons 1 and 2 of H-, K- and N-ras genes were screened for mutations by a combination of immunohistochemistry and single-strand conformational polymorphism (SSCP) analyses of polymerase chain reaction products from human surgical samples of both frank oral squamous cell carcinomas and premalignant lesions. The samples included 20 squamous cell carcinomas, 10 epithelial dysplasias and 10 epithelial hyperplasias. No identifiable gene mutations were detected in any of the dysplasias or hyperplasias, while 2 (10%) deletions and 2 (10%) mutations of p16/CDKN2, along with 5 (25%) p53 mutations were found in the advanced carcinomas, yielding characteristic p16/ CDKN2 and p53 changes. A mutation in the K-ras gene was found in single carcinoma and dysplastic samples. From the data, it can be argued that p16/CDKN2 and p53 mutations are relatively late occurrences in human oral tumorigenesis and that genetic alterations of the ras genes may not play a significant role in squamous neoplasia.

Carcinoma, Squamous Cell↗
PubMed1996

Detection of nitric oxide production and its role in pancreatic ischemia-reperfusion in rats.

Partial ischemia of rat pancreas body and tail was obtained by occlusion of the celiac axis for 1 h after gastrectomy. The plasma level of nitrite plus nitrate in both systemic and portal venous blood after reperfusion was significantly higher than that after sham operation and ischemia alone. The elevation after reperfusion was significantly decreased by NG-nitro-L-arginine methyl ester (L-NAME). Simultaneous administration of L-arginine counteracted the L-NAME-induced decrease in the level of nitric oxide (NO) end products. Generation of NO was further demonstrated by nitrosylhemoglobin detection by electron spin resonance in the blood after reperfusion. On the other hand, the plasma level of lipase, a marker of damage to pancreatic exocrine tissue, was significantly increased after ischemia-reperfusion and further increased by administration of L-NAME. This increase in lipase correlated with a decrease in tissue blood flow in the pancreas. These results suggest that NO is generated during and may have a protective role in ischemia-reperfusion of the rat pancreas.

Animals↗
PubMed1996

Involvement of ICE family proteases in apoptosis induced by reoxygenation of hypoxic hepatocytes.

Cell death due to reoxygenation after hypoxia was characterized in primary cultured hepatocytes. Fluorescence and electron microscopic analyses of reoxygenated hepatocytes revealed morphological characteristics of apoptosis, including chromatin condensation, nuclear fragmentation, and formation of apoptotic bodies. Few necrotic hepatocytes, defined by loss of plasma membrane integrity, mitochondrial swelling, and formation of large vacuoles, were observed. Activation of interleukin-1 beta-converting enzyme (ICE)-like and CPP32/Yama-like proteases, which are known to drive apoptosis, was observed during reoxygenation, and addition of their respective inhibitors inhibited the induction of apoptosis, indicating the involvement of ICE family proteases in apoptosis by reoxygenation. Production of oxygen radicals was enhanced by reoxygenation of hypoxic cells, and reoxygenation-induced apoptosis was inhibited by oxygen radical scavengers, suggesting a role for reactive oxygen species as a triggering factor in cell death. Electrophoretic analysis revealed the presence of 50-kb DNA fragments but not oligonucleosomal DNA fragments in reoxygenation-induced apoptotic hepatocytes.

Animals↗
PubMed1996

Mizoribine reduces urinary protein excretion in rats given puromycin aminonucleoside.

Mizoribine (MZR), a purine nucleoside antibiotic, is an effective immunosuppressive agent that prevents rejection reactions after kidney transplantation in humans. The present study was performed to examine the effect of MZR on nephrosis produced in rats given puromycin aminonucleoside (PAN). Urinary protein excretion in rats injected with PAN and MZR (PAN + MZR rats) was shown to be reduced significantly in comparison with rats given only PAN (PAN rats). Although mild hypoproteinemia persisted during the experimental period in PAN + MZR rats, no loss of body weight or state of malnutrition was observed. The reduction of serum IgG and C3 was reversed by administration of MZR. Polyethyleinamine (PEI) staining of renal sections showed increased numbers of anionic sites in PAN + MZR rats in comparison with PAN rats, suggesting that MZR improved the permselectivity of the glomerular basement membrane (GBM). Moreover, the production of thromboxane B2 (TxB2) was significantly inhibited in PAN + MZR rats compared with PAN rats. No serious adverse effects of MZR were observed after a large dose of the agent. It is possible that restoration of the charge barrier of the GBM damaged by PAN, or reduction of TxB2 production by the glomeruli may underlie the reduction of protein excretion induced by administration of MZR.

Animals↗
PubMed1996

Significance of serum lipase in patients undergoing hemodialysis.

Serum levels of lipase (Lp) during the end of the dialysis showed a significant increase after the administration of heparin in hemodialysis patients. However, serum Lp levels were not increased after the administration of the anti-coagulant nafamostat mesylate in hemodialysis patients. Serum levels of Lp were significantly correlated with serum levels of lipoprotein lipase (LPL), hepatic triglyceride lipase (H-TGL) and nonesterified fatty acid (NEFA) 20 min after the administration of heparin during maintenance hemodialysis. Lp activity did not appear with the NEFA ligand for determining the NEFA activity. Inhibitors of LPL and H-TGL reduced the measured Lp activity in vitro. The main mechanism of elevated measured serum Lp activity in hemodialysis patients was determined to be cross-reactivity with LPL or H-TGL. Furthermore, measurement of Lp may be a method for determining optimal coagulation time in patients with hemodialysis.

Adult↗
PubMed1996

Anti-inflammatory activities of 70% methanolic extract from Cinnamomi Cortex.

The effects of 70% methanolic extract (CC-ext) from Cinnamomi Cortex on acute and chronic inflammation were investigated. CC-ext inhibited the rise in vascular permeability induced by acetic acid and the increase of paw edema induced by carrageenin in mice. It was ineffective on edema derived by histamine or bradykinin, and exhibited only weak inhibitory effect on the edema derived by serotonin. CC-ext also showed inhibitory effects on the prekallikrein enzyme activity and ear edema induced by arachidonic acid. It also had an inhibitory effect on cotton pellet-induced granuloma but showed no atrophying action against the adrenal or thymus glands. Little effect was shown on secondary lesions in the development of adjuvant-induced arthritis (the arthritis reappeared from 11 to 27 d after injection of the adjuvant). These results suggest that some active component having an inhibitory effect on acute inflammation is contained in Cinnamomi Cortex.

Animals↗
PubMed1996

Potent immunosuppressive principles, dimeric sesquiterpene thioalkaloids, isolated from nupharis rhizoma, the rhizoma of Nuphar pumilum (nymphaeaceae): structure-requirement of nuphar-alkaloid for immunosuppressive activity.

Potent immunosuppressants, the dimeric sesquiterpene thioalkaloids, 6-hydroxythiobinupharidine (2), 6,6'-dihydroxythiobinupharidine (3), 6-hydroxythionuphlutine B (5) and 6'-hydroxythionuphlutine B (6), were isolated from a natural medicine, Nupharis Rhizoma, the rhizoma of Nuphar pumilum (TIMM.) DC., through bioassay-guided separation together with five quinolizidine alkaloids (8, 9, 10, 11, 12). Dimeric sesquiterpene thioalkaloids (2, 3, 5, 6) were found to significantly inhibit anti-sheep erythrocyte plaque forming cell formation in mice spleen cells at 10(-6) M concentration. At this concentration, 2, 5 and 6 were found to exhibit no cytotoxicity to mice spleen cells, and 3 also showed only a little cytotoxicity. In addition, the inhibitory activity of several Nuphar alkaloids, dimeric sesquiterpene thioalkaloids (1, 4, 7, 8), and monomeric sesquiterpene alkaloids (9, 10, 11, 12) on anti-sheep erythrocyte plaque forming cell formation was examined and some structural requirement of Nuphar alkaloid for immunosuppressive activity was determined.

Animals↗
PubMed1996

Studies of cuticle drugs from natural sources. IV. Inhibitory effects of some Arctostaphylos plants on melanin biosynthesis.

The inhibitory effect of 50% ethanol extracts obtained from the leaves of six Arctostaphylos plants (A. patula, A. viscida, A. canescens, A. columbiana, A. nevadensis and A. uva-ursi) (Ericaceae) was tested on melanin biosynthesis. Among them, the extracts of A. patula and A. viscida showed potent inhibition against tyrosinase. The two extracts not only inhibited the production of melanin from dopachrome by autoxidation, but exhibited SOD (superoxide dismutase)-like activity and had a moderate absorbance in the UV-B area. These results suggest that the leaves of Arctostaphylos plants, especially A. patula and A. viscida can be applied to a whitening agent for the skin.

Antioxidants↗
PubMed1996

Pharmacological study on Agkistrodon blomhoffii blomhoffii BOIE. V. anti-fatigue effect of the 50% ethanol extract in acute weight-loaded forced swimming-treated rats.

The anti-fatigue effect of 50% ethanol extract ([M]) from the dried whole body of Agkistrodon blomhoffii blomhoffii Boie, was investigated using an acute weight-loaded forced swimming (AWLFS) test by monitoring swimming times, blood biochemical parameters, thiobarbiturate-reactive substances (TBARS) as an index of lipid peroxide and antioxidative enzyme activities in blood and tissue. [M] (500 mg/kg/d), given orally for three successive days, significantly prolonged swimming times. It also inhibited the elevation of TBARS in plasma, liver, brain, kidney and soleus, and inhibited the lowering of catalase activity in erythrocyte, liver and soleus. However, it had no inhibitory effect on the elevation of creatine-kinase activity, free fatty acid and lactic acid levels or on the decrease in glucose level in serum. Also, it decreased the plasma TBARS level and increased the superoxide dismutase activity of plasma and erythrocytes in normal rats. From these results, it can be considered that [M] has an anti-fatigue effect.

Animals↗
PubMed1996

Medicinal foodstuff. III. Sugar beet. (1): Hypoglycemic oleanolic acid oligoglycosides, betavulgarosides I, II, III, and IV, from the root of Beta vulgaris L. (Chenopodiaceae).

Betavulgarosides I, II, III, and IV, oleanolic acid oligoglycosides having an unique acidic substituent, were isolated from the root of Beta vulgaris L. (sugar beet) together with betavulgarosides VI, VII, and VIII. The chemical structures of betavulgarosides I, II, III, IV were identified from chemical and physicochemical evidence. Betavulgarosides II, III, and IV were found to exhibit hypoglycemic activity in an oral glucose tolerance test in rats.

Animals↗
PubMed1996

New bioactive monoterpene glycosides from Paeoniae Radix.

Bioassay-guided separation of MeOH extract of Japanese Paeoniae Radix inhibiting contractile responses of guinea pig ileum stimulated with electric field disclosed a new monoterpene glycoside, 6-O-beta-D-glucopyranosyl-lactinolide (1), as an active constituent together with two new monoterpene glycosides (3 and 4) and two new monoterpenes (2 and 5). Furthermore, 1-O-beta-D-glucopyranosyl-paeonisuffrone (2) was found to inhibit histamine release from rat peritoneal exudate cells induced by antigen-antibody reaction.

Animals↗
PubMed1996

Bioactive saponins and glycosides. II. Senegae Radix. (2): Chemical structures, hypoglycemic activity, and ethanol absorption-inhibitory effect of E-senegasaponin c, Z-senegasaponin c, and Z-senegins II, III, and IV.

Following the characterization of E-senegasaponins a and b and Z-senegasaponins a and b, new bioactive saponins named E-senegasaponin c and Z-senegasaponin c were isolated from Senegae Radix, the root of Polygala senega L. var. latifolia TORREY et GRAY., together with Z-senegins II, III, and IV. The chemical structures of E and Z-senegasaponins c and Z-senegins II, III, and IV were elucidated on the basis of chemical and physicochemical evidence, and the geometrical isomeric structures of the 4"-methoxycinnamoyl and 3",4"-dimethoxycinnamoyl groups in these saponins were found to show tautomer-like behavior under irradiation with fluorescent lamps. E and Z-Senegasaponins c and E and Z-senegins II, III, and IV were found to exhibit hypoglycemic activity in the oral D-glucose tolerance test. (E) and (Z)-Senegins II also showed an inhibitory effect on alcohol absorption in rats.

Absorption↗
PubMed1996

Development of bioactive functions in hydrangeae dulcis folium. V. On the antiallergic and antimicrobial principles of hydrangeae dulcis folium. (2). Thunberginols C, D, and E, thunberginol G 3'-O-glucoside, (-)-hydrangenol 4'-o-glucoside, and (+)-hydrangenol 4'-O-glucoside.

Following the characterization of thunberginols A, B, and F, six bioactive principles, thunberginols C, D, and E, thunberginol G 3'-O-glucoside, (-)-hydrangenol 4'-O-glucoside, and (+)-hydrangenol 4'-O-glucoside, were isolated from Hydrangeae Dulcis Folium, the processed leaves of Hydrangea macrophylla SERINGE var. thunbergii MAKINO, together with four kaempferol and quercetin oligoglycosides. Their chemical structures have been determined on the basis of chemical and physicochemical evidence. Thunberginols C, D, E, and G and (-)-hydrangenol 4'-O-glucoside showed antiallergic activity in the in vitro bioassay using the Schultz-Dale reaction. These components also exhibited inhibitory activities on the histamine release from rat mast cells and on the histamine-induced contraction in isolated guinea pig tracheal chain. In addition, thunberginols C, D, E, and G showed antimicrobial activities against oral bacteria.

Animals↗
PubMed1996

Bioactive saponins and glycosides. III. Horse chestnut. (1): The structures, inhibitory effects on ethanol absorption, and hypoglycemic activity of escins Ia, Ib, IIa, IIb, and IIIa from the seeds of Aesculus hippocastanum L.

Five bioactive triterpene oligoglycosides named escins, Ia, Ib, IIa, IIb, and IIIa were isolated from the seeds of horse chestnut tree, Aesculus hippocastanum L. (Hippocastanaceae). The chemical structures of escins Ia, Ib, IIa, IIb, and IIIa were determine on the basis of chemical and physicochemical evidence, which included selective cleavage of the glucuronide linkage using photochemical reaction and lead tetraacetate decarboxylation reaction. Escins Ia, Ib, IIa, and IIb were found to exhibit an ethanol absorption-inhibitory effect and hypoglycemic activity in the oral glucose tolerance test in rats. Some structure-activity relationships are reported.

Animals↗
PubMed1996

Bioactive constituents of Chinese natural medicines. I. New sesquiterpene ketones with vasorelaxant effect from Chinese moxa, the processed leaves of Artemisia argyi Levl. et Vant.: moxartenone and moxartenolide.

Two new sesquiterpene ketones, moxartenone and moxartenolide, and three octadecadienoic acids were isolated from Chinese moxa, the processed leaves of Artemisia argyi LEVL. et VANT., together with two sesquiterpenes, five triterpenes, two phenyl propanoids and three polyoxyflavones. The chemical structures of new sesquiterpenes, moxartenone, moxartenolide, and octadecadienoic acids were determined on the basis of chemical and physiochemical evidence. Moxartenolide was found to inhibit the contractions induced by a high concentration of K+, by norepinephrine, and by serotonin in isolated aortic strips of rat, while moxartenone showed little activity.

Animals↗