Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0038358 (gastric ulcer)
 5,179 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

During experimental gastric ulceration in rats an elevation in the mucosal cAMP/cGMP ratio can be encountered. The cause of this significant elevation is mainly (but not entirely) the dramatic fall of the cGMP level. Similar observations were obtained with prostacyclin application (100 micrograms/kg, p.o.), too. This prostaglandin derivative is well known, among others, because of its pronounced anti-ulcerogenic (cytoprotective) effect, too. Other substances of different molecular structure and properties may also exert such effect. The exact mechanism of action of this above-mentioned cytoprotection is still not completely understood. H2-receptor blocker drug cimetidine, given in such small dose (5 mg/kg, p.o.) which does not interfere with gastric acid secretion, also exerts very significant cytoprotective effect in stress (restraint)- and drug (indomethacin)-induced gastric ulcer models. Under cimetidine effect--together with a noticeable endogenous prostacyclin mobilization--the gastric mucosal cAMP/cGMP ratio was also strongly elevated. We conclude that this elevation in the mucosal cAMP/cGMP ratio might be a possible molecular basis of the gastric cytoprotective (anti-ulcerogenic) drugs but it needs further investigations whether all substances exerting cytoprotective effect, e.g. atropine, somatostatin, sulfhydryl drugs, etc., have the same "shifting" property or not? Moreover the phenomenon of the so-called "adaptive cytoprotection" can not be ruled out completely either, therefore this problem needs attention, too.
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PMID:Gastric anti-ulcerogenic drug effect. A possible mechanism of its molecular basis. 134 9

The aims of this study were as follows: 1. to analyse the effects of drugs with different subcellular mechanisms on the PGI2-induced gastric cytoprotection in a non acid dependent (ethanol-induced) gastric ulcer model; 2. to identify the affinity and intrinsic activity curves on the PGI2-induced gastric cytoprotection; 3. to evaluate the main cellular mechanisms of PGI2-induced gastric mucosal defence. The observations were carried out on both sexes of CFY-strain rats, weighing 180 to 210 g. The gastric mucosal damage was produced by intragastric administration of 96% ethanol. The animals were killed at 1 hr after administration of ethanol, and the number and severity of gastric mucosal lesions (ulcers) was noted. Atropine, actinomycin D, cimetidine, mannomustine, dinitrophenol, epinephrine, pentagastrin, histamine, ouabain, tetracycline were given intraperitoneally (in different doses) at 30 min before administration of ethanol. The effects of these drugs were tested on the PGI2-induced (5 micrograms/kg was given intragastrically) gastric cytoprotection. It has been found that: 1. atropine, actinomycin D, cimetidine, epinephrine, ouabain, tetracycline and mannomustine inhibited the PGI2-induced gastric cytoprotection; 2. histamine, pentagastrin and 2,4-dinitrophenol enhanced the PGI2-induced gastric cytoprotection; 3. the molar concentrations of these drugs modifying the PGI2-induced gastric cytoprotection differed significantly. It has been concluded that: 1. the drugs stimulating or inhibiting the cell functions are capable to modify the extent of PGI2-induced gastric cytoprotection; 2. different subcellular mechanisms (oxidative phosphorylation, increased synthesis of proteins, ribonucleic and deoxyribonucleic acids, modifications of membrane-bound ATP-dependent energy systems) are involved in the development of PGI2-induced gastric cytoprotection.
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PMID:A pharmacological approach to cellular mechanisms of PGI2-induced gastric cytoprotection on ethanol-induced gastric mucosal damage in rats. 251 66

The healing process of acetic acid-induced gastric ulcer in rats was observed with an endoscope for 365 d after ulcer induction. The ulcers were induced by acetic acid solutions of various concentrations (2.5 (I), 5.0 (II), 10 (III) and 20% (IV); 0.05 ml). On day 3, a positive correlation was observed between the ulcer index (UI) and the concentration of acetic acid solution. On day 365, cumulative healing rates in groups I, II, III and IV amounted to 100, 100, 58.3 and 51.7%, respectively. The cumulative relapse rates in groups I, II, III and IV were 0, 13.6, 66.7 and 58.6%, respectively. Significant correlations were observed between initial UI values and cumulative healing or cumulative relapse rate. On day 365, rats were divided into two groups, a healed group and non-healed group, and the gastric mucosal prostaglandin I2 (PGI2) level was measured by bioassay. The PGI2 level around ulcers in ulcer-induced rats was higher than in normal rats, and it was higher in non-healed rats than in healed rats. Moreover, the PGI2 level was higher in those groups which showed a higher cumulative relapse rates. The above results indicated that the initial ulcer size and the PGI2 level around the ulcer might correlate to ulcer healing or exacerbation.
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PMID:Relapse of acetic acid-induced gastric ulcer and gastric mucosal prostaglandin I2 level in rats. 266 61

Synthesis of homoisocarbacyclin has been achieved efficiently by a general strategy with stereo- and regiochemical control. One of homoisocarbacyclin derivatives, 3-oxa homoisocarbacyclin analog (4), was shown to be potently active in inhibiting gastric ulcer. Another analog, conjugated diene derivative (5), was found to have a biological profile similar to prostacyclin.
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PMID:Synthesis of cis-bicyclo[4.3.0]non-2-ene derivatives. The potent homoisocarbacyclin analogs. 267 60

In 50 patients with gastric ulcer indices of oxygen tension (pO2) levels were investigated in correlation with the concentration of prostaglandins (E and F2 alpha), prostacyclin, thromboxane as well as with values of transmucous difference of potentials in different parts of the gastric mucosa, they were compared with 30 healthy controls. It has been assumed that the detected increase of reverse diffusion of hydrogen ions (the appearance of positive values of the transmembranous potential) and disorder of the ratio of prostanoids in favor of vasoconstrictors lead to a decrease in the blood flow and pO2 in the periulcerative zone of the patients with gastric ulcer. Hypoxia of the gastric mucosa is regarded as an important pathogenetic factor of ulcerogenesis.
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PMID:[The role of local factors regulating vascular blood flow in the development of hypoxia of the gastric mucosa in peptic ulcer]. 324 60

The newly identified plant-derived flavone-glycoside hypolaetin-8-glucoside, which has anti-inflammatory and gastric ulcer protective properties, and its corresponding aglycone, hypolaetin, were tested for effects on prostaglandin biosynthesis and degradation. They were compared with four other flavonoids, viz. rutin and its corresponding aglycone, quercetin, and the aglycones isoscutellarein and kaempferol. Over the range 10-1000 microM the glycosides rutin and hypolaetin-8-glucoside stimulated prostaglandin formation by sheep seminal vesicle microsomes incubated with radiolabelled arachidonic acid; the other compounds were essentially inactive. Over 5-5000 microM rutin and hypolaetin-8-glucoside enhanced the release of prostacyclin (and other prostanoids) from fragments of rat caecum incubated in the absence of additional arachidonic acid; the four aglycones compounds did not stimulate prostacyclin release but some reduced it at 5000 microM. However, the glycosides did not affect the enzymatic inactivation of radiolabelled prostaglandin F2 alpha by semi-purified bovine lung prostaglandin 15-hydroxydehydrogenase (PGDH) or in 100,000 g supernatants prepared from homogenised rat stomach. Three of the four aglycones (quercetin, kaempferol, isoscutellarein, in descending order of potency) were inhibitory to PGDH with ID50 values in the range 130-2100 microM. The results show that the capacity of flavonoids to enhance prostaglandin formation is associated with the presence of glycosidic substitution, whereas PGDH inhibition requires its absence. The relevance of this biochemical profile of hypolaetin-8-glucoside to its anti-inflammatory gastroprotective effects in vivo is discussed.
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PMID:Actions of flavonoids and the novel anti-inflammatory flavone, hypolaetin-8-glucoside, on prostaglandin biosynthesis and inactivation. 383 99

It is shown that de novo synthesis of protein is essential for the healing process of experimental gastric ulcer and that the cytoprotective effect of prostacyclin is connected with protein synthesis. In preliminary experiments the influence of prostacyclin on hepatic protein synthesis has also been shown.
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PMID:Cytoprotective effect of prostacyclin and protein synthesis. 619 37

Gastric ulcer was provoked by indomethacine (20 mg/kg s.c.) in rats. The ulcer protection by prostacyclin and cimetidine as well as the changes of tissue cAMP level in the gastric fundic mucosa--during ulcer-provocation and ulcer protection--were studied. The animals received prostacyclin (125, 250 and 500 micrograms/kg) and cimetidine (2.5 and 50 mg/kg) together with indomethacine. Evaluation of the results was undertaken 4 hours after the administration of the provoking agent. The number and severity of the ulcers as well as the cAMP level of the gastric fundic mucosa were measured. The following results were obtained: (1) cAMP level of the gastric fundic mucosa remained unaltered at the time of ulcer provocation; (2) cimetidine and prostacyclin reduced the number and severity of the ulcers in a dose-dependent manner; (3) cAMP level of the gastric fundic mucosa was reduced after cimetidine and prostacyclin treatment in a dose-dependent manner, the extent of which however did not show any correlation with the degree of ulcer-preventive action. The experimental results indicate that (1) the development of indomethacine-induced gastric ulcer is independent of the ATP--adenylate cyclase--cAMP system of the gastric fundic mucosa; (2) the ulcer protective action of cimetidine and prostacyclin is independent of tissue cAMP system of the gastric fundic mucosa in this model.
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PMID:The relationships between indomethacine-induced gastric ulcer, ulcer protection by cimetidine and prostacyclin and the cAMP system of the gastric fundic mucosa in the rat. 630 55

The effects of prostacyclin (PGI2) and its stable thia-thimo-analogue (Hoe 892) on gastric and intestinal secretions and gastric mucosal lesions have been determined in conscious rats. Both PGI2 and Hoe 892 given subcutaneously (s.c.) reduced dose-dependent gastric acid secretion, the ID50 (dose producing 50% inhibition) being about 48.6 and 11.8 micrograms/kg, respectively. In contrast, intragastric (i.g.) PGI2 and Hoe 892 did not cause any change in gastric acid secretion at doses ranging from 1 to 100 micrograms/kg. Both PGI2 and Hoe 892 reduced significantly intestinal fluid secretion (antienteropooling activity). PGI2 and Hoe 892 given i.g. or s.c. reduced dose-dependent gastric ulcer formation induced by acidified aspirin (ASA), Hoe 892 being somewhat less potent than PGI2. Both PGI2 and Hoe 892 were equally effective against gastric mucosal necrosis induced by absolute ethanol and this effect was observed both after i.g. and s.c. administration of these agents. We conclude that stable thia-imino-PGI2 analogue, Hoe 892, has similar gastric and intestinal antisecretory and protective activity as PGI2 and may be useful in the prevention of gastric damage by various noxious agents.
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PMID:Comparison of gastric and intestinal antisecretory and protective effects of prostacyclin and its stable thia-imino-analogue (Hoe 892) in conscious rats. 639 96

The effect of intragastric (i.g.) capsaicin on experimental gastric ulcer was studied in the 1 h pylorus-ligated rats. Capsaicin applied in 40 ng ml-1 concentration (0.1 microgram kg-1) protected against gastric mucosal injury evoked by i.g. application of acidified aspirin, 96% ethanol or 0.6 M HCl. After a capsaicin concentration of 400 micrograms ml-1 (1 mg kg-1) protection occurred initially, while several hours later mucosal damage evoked by acidified aspirin was enhanced. Capsaicin in 2 and 6 ml kg-1 (10 and 30 mg kg-1) invariably aggravated the aspirin and ethanol-induced gastric mucosal damage. Capsaicin in 0.1 microgram kg-1 did not modify the mucosal protective action of prostacyclin (5 micrograms kg-1) on gastric mucosal injury produced by i.g. application of acidified aspirin, 96% ethanol or 0.6 M HCl. Local capsaicin desensitization induced by application of capsaicin in 2 mg ml-1 (10 mg kg-1) did not interfere with the mucosal cytoprotective effects of prostacyclin against ethanol and aspirin-induced mucosal damage. It is concluded that i.g. capsaicin exerts a dual dose-dependent effect on development of experimental gastric ulcer. Neither i.g. capsaicin in small doses nor local capsaicin desensitization modify the mucosal cytoprotective effects of prostacyclin.
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PMID:Studies on the effect of intragastric capsaicin on gastric ulcer and on the prostacyclin-induced cytoprotection in rats. 886 36


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