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Biomedical subjects

F Ueda

Publications and source records attributed to F Ueda.

At least 73 records · Page 4Linked to original sources
PubMed1989

Inhibition of H+,K+-ATPase by methyl(E)-2-(3,4-dimethoxystyryl)-benzimidazole-4-carboxylate (ALE-36).

ALE-36, as well as omeprazole and SCH 28080, markedly inhibited the [14C]aminopyrine (AP) accumulation induced by dibutyryl cyclic AMP (dbcAMP) and H+,K+-ATPase activity in a concentration-dependent manner. The inhibitory effect of omeprazole on the dbcAMP-induced [14C]AP accumulation was reversed by treatment with beta-mercaptoethanol, but those of ALE-36 and SCH 28080 were not. ALE-36 and SCH 28080 did not inhibit dog renal Na+,K+-ATPase activity, while omeprazole and ouabain did inhibit this enzyme activity. These results suggest that the inhibitory action of ALE-36 on acid secretion is due to the specific inhibition of gastric H+,K+-ATPase, the manner being different from in the case of omeprazole.

Adenosine Triphosphatases↗
PubMed1989

Effects of ALE-36 on gastric secretion, and gastric and duodenal ulcers induced in rats.

We examined the antisecretory and anti-ulcer effects of ALE-36 in rats. ALE-36 (3-30 mg/kg) dose-dependently inhibited gastric acid secretion in pylorus-ligated rats. However, the agent apparently increased the volume of gastric juice, and the Na+ and Cl- ion outputs. These changes were almost completely prevented by pretreatment with indomethacin, suggesting that endogenous prostaglandins in the gastric mucosa mediated the changes. Pretreatment with ALE-36 (3-30 mg/kg) inhibited the development of stress-, aspirin-, and indomethacin-induced gastric lesions, and mepirizole-induced duodenal ulcers. Repeated administration of ALE-36 significantly accelerated the healing of gastric ulcers induced by thermocautery.

Animals↗
PubMed1988

Effects of zinc and EDTA on tissue cadmium in various smooth muscles in rabbit and guinea-pig.

1. The effects of zinc (Zn2+) and ethylenediaminetetra-acetic acid (EDTA) on tissue cadmium (Cd2+) were investigated in the smooth muscles of rabbit trachea, taenia coli, aorta and guinea-pig taenia coli. 2. After an Cd uptake in high-K2+ solution, samples were rinsed with cold high-K2+, cold Zn2+ or cold EDTA solution without Cd2+ and the results were quantitatively different from each other. 3. Concentration-response curves were obtained with each treatment of cold solution. 4. It is suggested that tissue Cd2+ can be divided into 3 fractions in the surface membrane and there is another fraction in cellular space.

Animals↗
PubMed1987

[Protective effect of dicloguamine maleate (MN-1695) on HCl-induced gastric mucosal damage in rats--histologic studies].

Effect of MN-1695, a new cytoprotective antiulcer agent, on 0.2 N HCl-induced gastric surface epithelial cell damage was investigated by optical and transmission electron microscopy in rats. Tissue examination after five minutes exposure to 0.2 N HCl showed extensive damage of the surface epithelial cells: dilatation of intercellular spaces including marked edema of lamina propria. It was found that MN-1695 (3 mg/kg) pretreatment prevented such 0.2 N HCl-induced damage of the surface epithelial cells, and it reduced the percentage of damaged mucosa, but not significantly.

Animals↗
PubMed1987

Interacting effects of zinc and cadmium on the cadmium distribution in the mouse.

Effects of zinc (Zn) on cadmium (Cd) distribution in the mouse body were investigated after intranasal administration. The amounts of Cd (2 x 10(-6) M/0.02 ml) reaching respiratory organs increased as the ip dose of pentobarbital increased. Administration of Zn with Cd (2 x 10(-6) M Zn + 2 x 10(-6) M Cd /0.02 ml) further increased the Cd amounts reaching respiratory organs and increased mouse mortality. A single administration of Cd increased Cd levels in blood, liver, kidney and respiratory organs. High levels of Cd were maintained for at least 90 days in these organs after single administrations of Cd. The administration of Cd plus Zn further increased the Cd content in these organs during 0-60 min after administration. However, simultaneous administration of Zn with Cd inhibited prolonged Cd accumulation in kidney and liver. These results suggest that intranasally administered Zn (2 x 10(-6) M) has dual effects on Cd movement. Zn further increases the Cd levels in the lung and mouse mortality increases. On the contrary, Zn inhibits prolonged Cd accumulation in mice and decreases the chronic toxicity in mice that survive the acute phase.

Administration, Intranasal↗
PubMed1985

Contractile effects of vanadate on monkey and rabbit tracheal smooth muscle.

The effects of vanadate (Na3VO4: VAN) on isolated tracheal smooth muscle of monkey (Macaca fascicularis) and rabbit were examined. VAN (10(-5)-10(-3) M) induced a sustained contraction in both tracheae which was not affected by atropine, tetrodotoxin or tripelennamine. Indomethacin potentiated VAN-induced contraction in monkey trachea but had no effect in rabbit trachea. In Ca-free solution, high K was ineffective whereas VAN or carbachol induced a small transient contraction. In both tracheae, the K-induced contraction was completely inhibited by verapamil while the VAN- and carbachol-induced contractions were partially inhibited by this inhibitor. Sodium nitroprusside was ineffective in rabbit trachea. In monkey trachea, however, K-induced contraction was completely inhibited and VAN- and carbachol-induced contractions were partially inhibited by sodium nitroprusside. Readmission of 5.4 mM K transiently relaxed the carbachol-induced contraction in trachea pretreated with a K-free solution. Ouabain completely and VAN partially inhibited this K-induced relaxation. VAN slightly increased the cellular Na content in rabbit trachea but not in monkey trachea. Previous inhibition of the Na pump activity by a K-free solution containing ouabain did not inhibit the VAN-induced contraction. It is concluded that VAN induces a transient, followed by a sustained contraction in both monkey and rabbit tracheae. The former contraction may be due to a release of cellular Ca and the latter to an influx of external Ca. VAN-induced contractions do not seem to be due to an inhibition of the Na pump activity.

Animals↗
PubMed1984

Effects of vanadate on mechanical and electrical activities in guinea-pig taenia coli.

Effects of vanadate (NH4VO3 and Na3 VO4: VAN) on electrical and mechanical activities and cellular Na content in guinea-pig taenia coli were examined. VAN (1-5 X 10(-4) M) transiently increased membrane potential and decreased muscle tension. Several minutes later, muscle tension increased following membrane depolarization and increase in spike frequency. The initial relaxing effect of VAN was not affected by ouabain, phentolamine and propranolol, and the contractile effect was not affected by atropine and tetrodotoxin. The VAN-induced contraction was dependent on external Ca and was abolished by verapamil. VAN also induced a contraction in depolarized taenia, which was augmented when external Ca concentration was lowered. VAN (10(-3) M) did not change cellular Na content. It is suggested that VAN-induced relaxation is due to the decrease in membrane electrical activities whereas contraction is attributable to the increased electrical activities followed by Ca influx and also to nonelectrical mechanism followed by mobilization of cellular Ca. These changes do not seem to be related to Na pump activity.

Animals↗
PubMed1984

Effect of 2,4-diamino-6-(2,5-dichlorophenyl)-s-triazine maleate (MN-1695) on gastric ulcers and gastric secretion in experimental animals.

The effect of 2,4-diamino-6-(2,5-dichlorophenyl)-s-triazine maleate (MN-1695) on various experimental gastric ulcers and gastric secretion in experimental animals was compared with that of cimetidine and cetraxate. MN-1695 significantly inhibited the formation of Shay, stress-induced, indomethacin-induced, and histamine-induced ulcers and significantly accelerated the healing of acetic acid-induced gastric ulcers. MN-1695 was much more effective in suppressing stress- and acetic acid-induced ulcers than indomethacin-induced, histamine-induced or Shay ulcers. Cimetidine was effective in preventing stress- and acetic acid-induced ulcers but had no significant effect on Shay, indomethacin-induced and histamine-induced ulcers. Cetraxate was effective in preventing only stress-induced ulcers and had almost no effect on other experimental ulcers. MN-1695 inhibited secretion of gastric juice, acid and pepsin in Shay rats, but had no influence on basal and secretagogue-stimulated acid secretion in the perfused stomach of urethanized rats. These findings suggest that MN-1695 is a new type of anti-ulcer agent.

Acetates↗
PubMed1984

Effect of 2,4-diamino-6-(2,5-dichlorophenyl)-s-triazine maleate (MN-1695) on gastric mucosal blood flow in dogs.

The effect of 2,4-diamino-6-(2,5-dichlorophenyl)-s-triazine maleate (MN-1695) on gastric mucosal blood flow ( GMBF ) and on the changes of GMBF induced by catecholamines, tetragastrin, histamine and indomethacin were investigated in anesthetized dogs. MN-1695 at doses up to 1 mumol/kg i.v. showed only a slight but prolonged increase of GMBF . MN-1695 tended to inhibit the decreases of GMBF induced by norepinephrine and the increase of GMBF induced by tetragastrin. The later phase of decreased GMBF induced by histamine was suppressed by MN-1695. However, MN-1695 had almost no effect on the increase of GMBF induced by epinephrine. MN-1695 produced a marked increase of antral mucosal blood flow which was reduced by pretreatment with indomethacin. Systemic blood pressure, respiration and the pressor responses induced by catecholamines and gastric secretagogues were not affected by MN-1695. These results suggest that MN-1695 may possess selective effects on the gastric mucosal microcirculation and that suppressive effects of MN-1695 on the GMBF decrease induced by ulcerogenic stimuli may be responsible for its anti-ulcer activities in various types of experimental gastric ulcers.

Animals↗
PubMed1984

Effect of 2,4-diamino-6-(2,5-dichlorophenyl)-s-triazine maleate (MN-1695) on gastric mucosal damage induced by various necrotizing agents in rats.

The effect of 2,4-diamino-6-(2,5-dichlorophenyl)-s-triazine maleate (MN-1695) on the gastric mucosal damage induced in rats by various necrotizing agents was compared with those of cimetidine, cetraxate and prostaglandin (PG) E2. MN-1695 at doses of 0.37 mg (1 mumol) to 3.72 mg (10 mumol)/kg, significantly decreased in a dose-dependent manner the damage indices after the application of ethanol, HCl, NaOH, 25% NaCl or boiling water. Cimetidine in doses of 12.6 mg (50 mumol) to 126 mg (500 mumol)/kg was effective only against HCl-induced damage. Cetraxate in doses of 34.2 mg (100 mumol) to 342 mg (1 mmol)/kg was effective against damage due to ethanol, HCl, 25% NaCl or boiling water. However, cetraxate increased the damage index of NaOH-induced injury. PGE2 in a dose of 25 micrograms (70 nmol)/kg was effective against ethanol and 25% NaCl. The histological changes of gastric mucosal cells produced by ethanol were significantly decreased by MN-1695 and PGE2. These results suggest that MN-1695 has a cytoprotective action like that of PGE2 and that this cytoprotection inhibits the development of various kinds of experimental gastric ulcers.

Animals↗
PubMed1983

High K-induced contractions in rabbit and monkey tracheal smooth muscle.

High K-induced contractions in rabbit and monkey tracheal smooth muscle were characterized. A substituted 60 mM K, 94.1 mM Na solution produced a sustained contraction in both preparations. The 60 mM K-induced contraction in rabbit trachea was inhibited by Ca removal, verapamil, glucose-removal and hypoxia but not by sodium nitroprusside. The 60 mM K-induced contraction in monkey trachea was inhibited by Ca removal, verapamil, sodium nitroprusside and hypoxia but not by glucose-removal. In rabbit trachea a substituted 154.1 mM K, Na deficient solution induced a rapid rise in tension followed by a gradual decrease. Wet weight of rabbit trachea increased in the 154.1 mM K solution. Both the decrease in the developed tension and the increase in the wet weight were prevented by the hyperosmotic addition of sucrose (50-100 mM). The decrease in the developed tension was also partially antagonized by the addition of pyruvate or oxalacetate. In monkey trachea, the sustained contraction induced by the 154.1 mM K solution showed very slow decrease following the increase in the wet weight of the tissue. The decrease in muscle tension was prevented by the addition of hyperosmotic sucrose. These results suggest that, in rabbit tracheal smooth muscle, the decrease in the developed tension in isosmotically substituted high K, Na deficient solution may be attributable mainly to the swelling of muscle cells and partly to the inhibition of glucose utilization resulting from Na deficiency. In contrast, the contraction in monkey trachea seems to be inhibited, although slightly, by the swelling of the cells.

Animals↗
PubMed1982

Inhibitory effects of vanadate on the contractile responses in vascular smooth muscle.

The effects of vanadate (Na3VO4) on the contractions induced by high concentrations of K, histamine and norepinephrine in isolated guinea-pig aorta were investigated. Vanadate (10(-3) M) relaxed the high K contraction only when the external K concentration was above 85.4 mM. Vanadate showed no inhibitory action on the contraction induced by either Na-containing 45.4 mM K solution or Na-poor 45.4 mM K solution. Ouabain (2 X 10(-5) M) had no inhibitory effects on the contractions induced by these high K solutions. Vanadate failed to relax the contraction induced by histamine or norepinephrine in normal (5.4 mM) medium, while it inhibited the contraction in the presence of 142.2 mM K. Ouabain also did not inhibit the histamine- or norepinephrine-induced contraction in either normal or high K solution. These results suggest that the inhibitory actions of vanadate are not due to an inhibition of Na pump and that these effects depend on the presence of a high concentration of external K ions.

Animals↗
PubMed1982

Dual actions of vanadate on high K-induced contraction in guinea-pig taenia coli.

Effects of vanadate (NH4VO3: VAN) on tension development, membrane potential and cellular Na content were investigated in guinea-pig taenia coli depolarized by 62.7 mM KCl solution. VAN (10(-4) - 10(-3) M) caused a transient increase in the K developed tension followed by a relaxation. The VAN-induced contraction was observed even in a low Ca (0.13 mM) solution but was inhibited by the removal of external Ca. After the addition of verapamil (5 x 10(-8), 10(-7) M). VAN still produced a contraction. Further, the VAN-induced contraction was observed in 142.2 mM KCl (Na 11.9 mM) solution containing ouabain (10(-4) M). On the other hand, the effect of VAN to relax the K-induced contraction was dependent on the concentration of VAN. In low Na (choline-substituted) solution, the VAN-induced relaxation was decreased. VAN increased cellular Na content of the depolarized muscle, and a correlation was obtained between the cellular Na accumulation and the relaxation. These results suggest that the relaxation is mainly attributable to the accumulation of Na following the inhibition of the Na pump, while the contraction is independent of the inhibition of the Na pump and less sensitive to the external Ca than the K-induced process.

Animals↗