Indomethacin is used widely in clinics nowadays and the side effect of ulceration is well known. This experiment was performed to Study the morphological and histochemical changes on gastric mucosa after indomethacin treatment. The microscopic finding of the mucosa was observed following oral administration of 10 mg/kg indomethacin in alcohol as solvent. The histological changes were observed from 6 hours after administration of indomethacin and the maxima1 injury was found at 24 hours. Structural changes of injury included hemorrhage, epithelial desquamation and inflammatory cell infiltration. From the 3 day specimens, regeneration signs had started and in the 6 day specimens almost complete recovery of the mucosal epithelium was noted. The histochemical changes of the mucus were also observed from the 6 hr specimens. As far as neutral glycoprotein was concerned, the decrease was most significant in the 3 day o1d group, and besides, they showed minimal reaction to PAS stain. For acidic mucus, the decrease was significant in the 24 hr group and the 3 day group showed minimal reaction to Alcian blue stain. It was noted that these changes of the mucus had recovered 6 days after the administration of indomethacin.
Animal ; Gastric Mucosa/drug effects* ; Gastric Mucosa/pathology ; Indomethacin/adverse effects* ; Rats ; Rats, Inbred Strains ; Stomach Ulcer/chemically induced ; Time Factors

Ethanol causes mucosal injury to the stomach and which accompanied by back-diffusion of H+. Using several drugs known to modify the gastric acid secretion and to provide cytoprotection the effect of back-diffusion of H+ by ethanol was examined. Following 48 hours of starvation rats were anesthetized with urethane, and their stomachs were filled with 4 ml of 20% ethanol solution containing 1.8 mM HCI (7.2 microEq/4 ml) every 15 min. H+ content of the collected perfusates was determined by back-titration to pH 6.0. The presence of ethanol in the stomach for 1 hour caused a loss of luminal H+ at a rate of 4.8 +/- 0.4 microEq/15 min. Pretreatment of rats with atropine (2 mg/Kg, i.v.), pirenzepine(2 mg/Kg. i.v.), cimetidine (10mg/Kg i.v.), cromolyn sodium (20mg/Kg/hr, i.v.) or domperidone (1 mg/kg. i.v.) did not affect the ethanol-induced H+ back-diffusion. Similarly, no effect was seen in rats treated with prostaglandin E2 (100 microgram/Kg i.v.) or indomethacin (5 mg/Kg, s.c). The addition of procaine (10(-5)~10(-3) M) or propranolol (10(-9)~10(-5) M) to the perfusate did not cause any changes in the ethanolinduced H+ back-diffusion. However, pretreatment of rats with acetazolamide (100 mg/Kg i.v.) or ethoxzolamide(50 mg/Kg/day, p.o. for 6 days), carbonic anhydrase inhibitors, markedly suppressed the ethanol-induced loss of luminal H+. Based on these results, it is suggested that ethanol-induced back-diffusion of H+ is mediated, at least in part, by the activity of carbonic anhydrase, and that cholinergic, histaminergic and dopaminergic mechanisms are not involved. Moreover, the implications of prostaglandins and membrane stability are not suggested.
Absorption ; Animal ; Diffusion ; Ethanol/pharmacology* ; Female ; Gastric Acid/secretion* ; Gastric Mucosa/drug effects* ; Male ; Parasympatholytics/pharmacology ; Protons* ; Rats

No abstract available.
Adenoma ; Gastric Mucosa ; Helicobacter Infections ; Helicobacter pylori/*drug effects ; Humans ; *Time

Acetylcholine ; pharmacology ; Adenocarcinoma ; metabolism ; Cell Line, Tumor ; Gastric Mucosa ; cytology ; drug effects ; metabolism ; Humans ; Receptors, Cholinergic ; metabolism ; Stomach Neoplasms ; metabolism

AIMTo investigate the effects of calcitonin gene-related peptide (CGRP), gastrin 17 (G17), bombesin (Bom), met-enkephalin (Met-enk), neuropeptide Y (NPY) and somatostatin (SS) on GMBF and the role of endogenous NO in increased GMBF induced by neuropeptides in rats.

METHODSBy hydrogen gas clearance technique to measure gastric mucosal blood flow (GMBF) and arterial infusion close to stomach or intracerebroventricular (icv) to microinject neuropeptides.

RESULTS(1) Arterial infusions of CGRP and G17 (5, 50 and 100 pmol x min(-1)) increased GMBF significantly in dose-dependent manners. CGRP had more effective effect on increasing GMBF than that of G17. Intravenous pretreatment of L-nitro-L-arginine methyl ester (L-NAME) to inhibit the synthesis of endogenous NO could abolish completely or partially the increases in GMBF response to CGRP or G17 respectively. (2) Arterial infusions of Bom and Met-enk (50 and 100 pmol x min(-1)) increased GMBF significantly. The increases in GMBF induced by Bom or Met-enk were abolished completely or partially by pretreatment of L-NAME respectively. (3) Arterial infusion of NPY (5, 50 and 100 pmol x min(-1)) led to reduction of GMBF significantly in a dose-dependent manner. SS (50 and 100 pmol x min(-1)) also reduced GMBF significantly. (4) icv microinjection of CGRP (10 microg) and G17 (10 Microg) increased GMBF significantly. The increases in GMBF induced by icv microinjection of CGRP or G17 were blocked completely or partially respectively by pretreatments with L-NAME. (5) icv microinjection of NPY (10 microg) decreased GMBF significantly.

CONCLUSIONNeuropeptides play important roles in the regulation of GMBF in rats and NO is involved in the increase of GMBF induced by some neuropeptides.

Animals ; Gastric Mucosa ; blood supply ; drug effects ; Male ; Neuropeptides ; pharmacology ; physiology ; Nitric Oxide ; physiology ; Rats ; Rats, Sprague-Dawley

AIMTo investigate the effects of sodium sulfonate daidzein (SSD) on stress-induced gastric ulcer and explore its possible mechanism.

METHODSUsing exhausted swimming and counting the number of gastric ulcer to establish the model of stress-induced gastric ulcer. Mouse experience intraperitoneal injection of different doses of SSD and L-NAME, and NDP histochemical method was used to detect the changes of nitric oxide synthase (NOS) positive neurons in stomach.

RESULTSSSD had dose-dependent protective effect on gastric mucosa. L-NAME could prevent stress induced gastric lesion. After combined injection of L-NAME and effective dose of SSD, the protective effect of SSD on gastric mucosa was reinforced. The number of NOS ganglion was constant, and effective dose of SSD had slight effect on NOS-positive neurons in normal mouse while it decreased NOS positive neurons in per area and in per ganglia after stress.

CONCLUSIONThe increased nitric oxide (NO) leads to gastric ulcer during stress, SSD has protective effect on gastric mucosa and this effect may be mediated by inhibiting NOS and restricting the overproduction of NO during stress.

Animals ; Gastric Mucosa ; drug effects ; pathology ; Isoflavones ; pharmacology ; Male ; Mice ; Mice, Inbred ICR ; Nitric Oxide ; metabolism ; Stomach Ulcer ; Stress, Physiological

AIM AND METHODSBy hydrogen gas clearance technique to measure gastric mucosal blood flow (GMBF) and a high dose of capsaicin to ablate the capsaicin-sensitive afferent fibers, the roles of capsaicin-sensitive afferent fibers and endogenous NO in the gastric acid secretion and hyperemic response to intragastric distention were studied in rats.

RESULTS(1) There was an increase in acid secretion associated with the increase in GMBF to intragastric distention. (2) Pretreatment with a high dose of capsaicin to ablate afferent fibers completely abolished the GMBF and partially inhibited the acid secretion during the intragastric distention. (3) The increase in GMBF to intragastric distention was completely blocked by pretreatment with L-NAME, whereas the acid secretion was significantly attenuated.

CONCLUSIONCapsaicin-sensitive afferent fibers and endogenous NO are involved in the increases of gastric acid secretion and GMBF.

Animals ; Capsaicin ; pharmacology ; Gastric Acid ; secretion ; Gastric Dilatation ; metabolism ; Gastric Juice ; secretion ; Gastric Mucosa ; blood supply ; Male ; NG-Nitroarginine Methyl Ester ; Neurons, Afferent ; drug effects ; Nitric Oxide ; physiology ; Rats ; Rats, Sprague-Dawley

Acetylcholine ; pharmacology ; Cell Line, Tumor ; Cell Membrane ; Epithelial Cells ; cytology ; Gastric Mucosa ; cytology ; drug effects ; metabolism ; Humans ; Receptors, Nicotinic ; drug effects ; metabolism ; Stomach Neoplasms ; metabolism

OBJECTIVETo study the regulative action of mica monomer powder preparation on the chief and parietal cells as well as G and D cells in the gastric mucosa of the experimental atrophic gastritis (CAG) rats.

METHODSIntervention therapy was given to the experimental CAG rats at three different doses of mica monomer powder preparation to evaluate the changes of chief and parietal cells as well as G and D cells in the gastric mucosa and the histopathological changes of gastric mucosa.

RESULTSMica monomer powder preparation at three different doses could increase the amount of chief and parietal cells as well as G and D cells in gastric mucosa of the experimental CAG rats and alleviate and control the inflammation of gastric mucosa and the atrophy of gastric mucosa glands. Especially, better effects were shown in the mid and high dose groups.

CONCLUSIONMica has the pharmacological action of protecting the gastric mucosa, enhancing blood flow of the gastric mucosa, and consequently improving the inflammatory responses of the gastric mucosa. One of the mechanisms is associated with promoting the secretion of gastric acid and gastric pepsin and regulating the neuroendocrine mechanism including gut hormone secretion (gastrin and somatostatin) by increasing the number of chief and parietal cells as well as G and D cells.

Aluminum Silicates ; pharmacology ; Animals ; Cell Count ; Chief Cells, Gastric ; drug effects ; pathology ; Chronic Disease ; Gastric Mucosa ; drug effects ; pathology ; Gastrin-Secreting Cells ; drug effects ; pathology ; Gastritis, Atrophic ; pathology ; Inflammation ; Parietal Cells, Gastric ; drug effects ; pathology ; Powders ; Rats ; Rats, Sprague-Dawley ; Somatostatin-Secreting Cells ; drug effects ; pathology

AIMTo study the influence of acetylcholine (ACh) on nicotinic receptor(N receptor) beta-subunit of the gastric epithelia and the gastric adenocarcinoma cells, and the difference of both cells.

METHODSImmunohistochemistry method was used to examine the number, number density and surface density of N receptor beta-subunit in both cells cultured in vitro.

RESULTSThe number and number density of N receptor beta-subunit in the gastric adenocarcinoma cells were much more than that in the gastric epithelia (P < 0.05). But surface density of N receptor beta-subunit in the gastric adenocarcinoma cells were lower than that in the gastric epithelia (P < 0.05). ACh at 10(6) mol/L could increase the number, number density and surface density of N receptor beta-subunit in the gastric epithelia (P < 0.01). The increase effect could not be blocked by atropine. ACh had no effect on N receptor beta-subunit in the gastric adenocarcinoma cells.

CONCLUSIONACh at low concentration initiates N receptor desensitization in the gastric epithelia. ACh has no effect on sensitivity of N receptor beta-subunit in the gastric adenocarcinoma cells.

Acetylcholine ; pharmacology ; Adenocarcinoma ; metabolism ; Cells, Cultured ; Epithelial Cells ; drug effects ; Gastric Mucosa ; cytology ; Humans ; Receptors, Nicotinic ; metabolism ; Stomach Neoplasms ; metabolism ; Tumor Cells, Cultured