Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0847097 (acidity)
 15,165 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Gastric mucosal adaptation to injury by repeated application of stress is a well known phenomenon. This study was designed to determine the effect of gastric acid inhibition by ranitidine on gastric adaptation to repeated exposures to stress. In this study stress 3.5 h of water immersion and restraint stress (WRS) was provoked once in rats with and without pretreatment of ranitidine (40 mg/kg/s.c.) and gastric adaptation was examined by repeated exposures to 3.5 h of WRS applied every other day for up to 8 days with pretreatment with vehicle (control), with pretreatment with ranitidine (40 mg/kg/s.c.) and with withdrawal of ranitidine prior to the last exposure to WRS. Luminal acidity, mean lesion number, histology and cell proliferation (PCNA-labeling index) were determined and the expression of EGF and TGF alpha was assessed by immunohistochemistry. Pretreatment with ranitidine increased significantly luminal acidity and WRS applied once with ranitidine pretreatment resulted in a significant decrease of number of lesions. Gastric mucosa adapted to repeated WRS did show a reduction in the mean lesion number by about 60% as compared to that induced by WRS applied once. About 3 fold increase in the expression of EGF was observed in the group adapted to repeated WRS. Expression of TGF alpha was not significantly different from that in intact rats. We conclude that gastric adaptation to stress leads to a decrease in gastric lesions and to an increase in expression of EGF. Pretreatment with ranitidine that induces achlorchydria results in additional reduction in the number of stress lesions.
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PMID:Adaptation of gastric mucosa to stress. Effect of ranitidine. 978 93

Polyglycolic acid (PGA) is commonly used as a scaffold for tissue engineering. Recent studies utilized PGA as a scaffold for vascular tissue engineering using bovine and porcine smooth muscle cells (SMCs). In engineered vessels, the SMCs displayed high rates of mitosis and dedifferentiation in areas where PGA fragments were present. We hypothesized that PGA breakdown products, sequestered within a SMC vessel at the conclusion of culture, led to increased proliferation and dedifferentiation of vascular SMCs. To test this hypothesis, the current study assessed possible means by which PGA breakdown products could lead to changes in SMC phenotype. SMCs grown in high concentrations of PGA breakdown products showed, by Western blotting, decreased expression of calponin, a marker for SMC differentiation. The same was true for SMCs grown in glycolic acid (GA), which also showed decreased expression of proliferating cell nuclear antigen (PCNA), a marker for SMC proliferation. In contrast, cells grown in varying amounts of NaCl or HCl showed little change in differentiation. We conclude that, independent of acidity or osmolality, plausible products of PGA degradation appear to induce dedifferentiation of porcine SMCs in vitro. Because of dedifferentiation and decreased mitosis, commercially available PGA may not represent an optimal scaffold for vascular tissue engineering.
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PMID:Effects of polyglycolic acid on porcine smooth muscle cell growth and differentiation. 1451 89

We investigated the protective effects of chemical stimulation of cerebellar interpositus nucleus (IN) on gastric ischemia-reperfusion injury (GI-RI) and its possible regulatory mechanisms in rats. Gastric mucosal damage index (GMDI) indicated the severity of gastric mucosal injuries. Transferase dUTP nick end labeling (TUNEL) staining and proliferating cell nuclear antigen (PCNA) were performed to assess gastric mucosal cell apoptosis and proliferation. Microinjection of glutamate into IN markedly attenuated GI-RI. Either chemical lesion of IN or electrical ablation of the decussation of superior cerebellar peduncle (DSCP) obviously aggravated GI-RI. The protective effects of IN were reversed with the pretreatments of microinjection of 3-mercaptopropionic acid into IN or Bicuculline into lateral hypothalamic area (LHA), individually. The discharge frequency and intensity of greater splanchnic nerve (GSN) decreased and gastric mucosal blood flow increased after chemical stimulation of IN. The apoptosis of positive cells of gastric mucosa was decreased by chemical stimulation of IN, whereas proliferation increased. The gastric juice volume, acidity, and total acid output were all decreased after the chemical stimulation of IN. These results indicated that IN participates in regulation of GI-RI and is a specific area in central nervous system for exerting protective effects on GI-RI. DSCP, LHA and GSN may involve in this process. Apoptosis and proliferation may mediate this protective process in rats too.
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PMID:Lateral hypothalamic area mediated the protective effects of microinjection of glutamate into interpositus nucleus on gastric ischemia-reperfusion injury in rats. 2284 93

We evaluate the curative efficacy of the ethanolic extract (EET) of roots from Arctium lappa (bardana) in healing of chronic gastric ulcers induced by 80% acetic acid in rats and additionally studies the possible mechanisms underlying this action. Oral administration of EET (1, 3, 10 and 30mg/kg) reduced the gastric lesion area in 29.2%, 41.4%, 59.3% and 38.5%, respectively, and at 10mg/kg promoted significant regeneration of the gastric mucosa, which was confirmed by proliferating cell nuclear antigen immunohistochemistry. EET (10mg/kg) treatment did not increase the gastric mucus content but restored the superoxide dismutase activity, prevented the reduction of glutathione levels, reduced lipid hydroperoxides levels, inhibited the myeloperoxidase activity and reduced the microvascular permeability. In addition, EET reduced the free radical generation and increased scavenging of 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals in vitro. Furthermore, intraduodenal EET (10 and 30mg/kg) decreased volume and acidity of gastric secretion. Total phenolic compounds were high in EET (Folin-Ciocalteau assay) and the analysis by liquid chromatography-mass spectrometry revealed that the main compounds present in EET were a serie of hydroxycinnamoylquinic acid isomers. In conclusion, these data reveal that EET promotes regeneration of damaged gastric mucosa, probably through its antisecretory and antioxidative mechanisms.
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PMID:Ethanolic extract of roots from Arctium lappa L. accelerates the healing of acetic acid-induced gastric ulcer in rats: Involvement of the antioxidant system. 2303 53

Hyptis martiusii Benth. is an aromatic plant found in abundance in northeastern Brazil that is used in ethnomedicine to treat gastric disorders. The aim of this study was to elucidate the mechanisms of action involved in the gastroprotection of the essential oil of Hyptis martiusii (EOHM) and to evaluate its healing capacity. Wistar rats were exposed to different protocols and subsequently were treated with 1% Tween-80 aqueous solution (negative control), pantoprazole, carbenoxolone, N-acetylcysteine (depending on the specificity of each model) or EOHM. The antisecretory activity (basal or stimulated) was determined using the pyloric ligature method. The gastroprotective action of nitric oxide and sulphydryl groups (-SH groups), as well as the quantification of adherent mucus and the levels of malondialdehyde and -SH groups in gastric mucosa, were evaluated using ethanol-induced gastric ulcer model. The healing ability was evaluated using the acetic acid-induced gastric ulcer model and histological and immunohistochemical analysis (HE, PAS and PCNA). EOHM (400 mg/kg) reduced the volume and acidity of gastric secretion stimulated by histamine and pentagastrin. The gastroprotective effect of EOHM involves the participation of endogenous sulfhydryl groups. EOHM increased mucus production (54.8%), reduced levels of MDA (72.5%) and prevented the depletion of -SH groups (73.8%) in the gastric mucosa. The treatment with EOHM reduced in 70.3% the gastric lesion area, promoting significant regeneration of the gastric mucosa, as confirmed by histological analysis and analysis of proliferating cell nuclear antigen. The results show that gastroprotective effect of EOHM is mediated by cytoprotective and antioxidant mechanisms and by their antisecretory activity, and suggest that the essential oil of Hyptis martiusii is a promising candidate for the treatment of gastric ulcers.
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PMID:Gastroprotective and ulcer healing effects of essential oil of Hyptis martiusii Benth. (Lamiaceae). 2445 26