Effects of extract F of red-rooted Salvia on mucosal lesions of gastric corpus and antrum induced by hemorrhagic shock-reperfusion in rats

AIM: To compare the effects of extract F of red-rooted Salvia (EFRRS) on mucosal lesions of gastric corpus and antrum induced by hemorrhagic shock and reperfusion in rats. METHODS: The rats were subject to hemorrhagic shock and followed by reperfusion, and were divided randomly into two groups. Group 1 received saline, and group 2 received EFRRS intravenously. The index of gastric mucosal lesions (IGML) was expressed as the percentage of lesional area in the corpus or antrum. The degree of gastric mucosal lesions (DGML) was catalogued grade 0,1,2 and 3. The concentrations of prostaglandins (PGs) were measured by radioimmunoassay. The concentration of MDA was measured according to the procedures of Asakawa. The activity of SOD was measured by the biochemical way. The growth rates or inhibitory rates of above-mentioned parameters were calculated. RESULTS: As compared with IGML (%), grade 3 damage (%) and MDA content (nmol/g tissue) of gastric antrum which were respectively 7.96 +/- 0.59, 34.86 +/- 4.96 and 156.98 +/- 16.12, those of gastric corpus which were respectively 23.18 +/- 6.82, 58.44 +/- 9.07 and 230.56 +/- 19.37 increased markedly (P 【0.01), whereas the grade 0 damage, grade 1 damage, the concentrations of PGE(2) and PGI(2)(pg/mg tissue), the ratio of PGI(2)/TXA(2) and the activity of SOD (U/g tissue) of corpus which were respectively 3.01 +/- 1.01, 8.35 +/- 1.95, 540.48 +/- 182.78, 714.38 +/- 123.74, 17.38 +/- 5.93 and 134.29 +/- 13.35 were markedly lower than those of antrum which were respectively 13.92 +/- 2.25, 26.78 +/- 6.06, 2218.56 +/- 433.12, 2531.76 +/- 492.35, 43.46 +/- 8.51 and 187.45 +/- 17.67 (P【0.01) after hemorrhagic shock and reperfusion.After intravenous EFRRS, the growth rates (%) of grade 0 damage, grade 1 damage, the concentrations of PGE(2) and PGI(2), the ratio of PGI(2)/TXA(2) and the activity of SOD of corpus which were respectively 632.56, 308.62, 40.75, 74.75, 92.29 and 122.25 were higher than those in antrum which were respectively 104.89, 58.40, 11.12, 56.58, 30.65 and 82.64, whereas the inhibitory rates (%) of IGML, grade 3 damage and MDA content of gastric corpus were 82.93, 65.32 and 59.09, being higher than those of gastric antrum which were 76.64, 53.18 and 42.37. CONCLUSION: After hemorrhagic shock reperfusion, the gastric mucosal lesions in the corpus were more severe than those in the antrum, which were related not only to the different distribution of endogenous PGs in the mucosa, but also to the different ability of anti-oxidation of the mucosa. The protective effect of EFRRS on the gastric mucosa in the corpus was more evident than that in the antrum, which was related to higher growth degree of PGs contents and anti-oxitative ability in gastric corpus after administration of EFRRS.

Gastrin,somatostatin,and experimental disturbance of the gastrointestinal tract in rats

INTRODUCTIONThe field of gastrointestinal hormones has expanded at a dizzying rate[1-4].Gastrointestinal hormones as regulatory peptides that appear to be major components of bodily integration and have important regulatory actions on physioligical function of the gastrointestinal tract .The successful isolation of some gastrointestinal hormones and the development of sensitive methods for their detection have led to the unexpected finding that they also exist in the brain .

Low grade gastric mucosa associated lymphoid tissue lymphoma:Treatment strategies based on 10 year follow-up

AIM:To deduce strategic guidelines of gastric mucosa associated lymphoid tissue lymphoma (MALTOMA) by evaluating the long-term outcome of patients in respect to various treatment modalities. METHODS:A total of 55 patients with MALTOMA from May 1992 to August 2002 were retrospectively reviewed. RESULTS:Complete remission was obtained in 24 (82.8%) of 29 patients treated with anti Helicobacter pylori (Hpylori) regimen only.The duration to reach complete remission was 12 months (85 percentile,2-33 months).Five patients showed complete remission with radiation therapy (26-86 months).Two of them were Hpyloritreatment failure cases. CONCLUSION:Hpylorieradication is an effective primary treatment option for low grade MALTOMA and radiation therapy could be considered in patients with no evidence of Hpyloriinfection or who do not respond to Hpylorieradication therapy 12 months after successful eradication.

Interobserver variation in histopathological assessment of Helicobacter pylori gastritis

AIM:Because the presence or absence of H pylori infection has important implications for therapeutic decisions based on histological assessment,the reproducibility of Sydney system is important.The study was designed to test the reproducibility of features of Helicobacter pylori gastritis, using the updated Sydney classification. METHODS:Gastric biopsies of 40 randomly selected cases of H pylori gastritis were scored semiquantitatively by three pathologists.Variables analysed induded chronic inflammation, inflammatory activity,atrophy,intestinal metaplasia,H pylori, surface epithelial damage.κ values below 0.5 represented poor,those between 0.5 and 0.75 good and values over 0.75 excellent interobserver agreement. RESULTS:The best interobserver agreement(κ=0.62)was present for intestinal metaplasia.The agreement was the poorest for evaluating atrophy(κ=0.31). CONCLUSION:Although the results of this study were in accordance with some previous studies,an excellent agreement could not be reached for any features of H pylori gastritis.This low degree of concordance is assumed to be due to the personal evaluation differences in grading the features,the lack of standardized diagnostic criteria,and the ignorance to reach a consensus about the methods to be used in grading the features of H pylori gastritis before initiating the study.

Epithelial cell proliferation and glandular atrophy in lymphocytic gastritis: Effect of H pylori treatment

AIM:Lymphocytic gastritis is commonly associated with Helicobacter pylori infection.The presence of glandular atrophy and foveolar hyperplasia in lymphocytic gastritis suggests abnormalities in cell proliferation and differentiation, forming a potential link with the suspected association with gastric cancer.Our aim was to compare epibhelial cell proliferation and morphology in H pylori associated lymphocytic gastritis and H pylori gastritis without features of lymphocytic gastritis, and to evaluate the effect of H pylori treatment. METHODS:We studied 14 lymphocytic gastritis patients with H pylori infection.For controls,we selected 14 matched dyspeptic patients participating in another treatment trial whose H pylori infection had successfully been eradicated. Both groups were treated with a triple therapy and followed up with biopsies for 6-18 months (patients) or 3 months (controls).Blinded evaluation for histopathological features was carried out.To determine the cell proliferation index, the sections were labeled with Ki-67 antibody. RESULTS:Before treatment,lymphocytic gastritis was characterized by foveolar hyperplasia (P=0.001) and glandular atrophy in the body (P=0.008),and increased proliferation in both the body (P=0.001) and antrum (P=0.002).Proliferation correlated with foveolar hyperplasia and inflammation activity.After eradication therapy,the number of intraepithelial lymphocytes decreased in the body (P=0.004) and antrum (P=0.065),remaining higher than in controls (P<0.001).Simultaneously,the proliferation index decreased in the body from 0.38 to 0.15 (P=0.043),and in the antrum from 0.34 to 0.20 (P=0.069),the antral index still being higher in lymphocytic gastritis than in controls (P=0.010). Foveolar hyperplasia and glandular atrophy in the body improved (P=0.021),reaching the non-LG level.CONCLUSION: In lymphocytic gastritis, excessive epithelialcell proliferation is predominantly present in the body, where it associates with foveolar hyperplasia and glandular atrophy. These characteristic changes of lymphocytic gastritis are largely related to H pylori infection, as shown by their improvement after eradication. However, some residualdeviation was still seen in lymphocytic gastritis, indicating either an abnormally slow improvement or the presence of some persistent abnormality.

Mechanisms mediating cholinergic antral circular smooth muscle contraction in rats

AIM:To investigate the pathway(s)mediating rat antral circular smooth muscle contractile responses to the cholinomimetic agent,bethanechol and the subtypes of muscarinic receptors mediating the cholinergic contraction. METHODS:Circular smooth muscle strips from the antrum of Sprague-Dawley rats were mounted in muscle baths in Krebs buffer.Isometric tension was recorded.Cumulative concentration-response curves were obtained for(+)-cis- dioxolane(cD),a nonspecific muscarinic agonist,at 10^(-8)- 10^(-4)mol/L,in the presence of tetrodotoxin(TTX,10^(-7)mol/L). Results were normalized to cross sectional area.A repeat concentration-response curve was obtained after incubation of the muscle for 90 min with antagonists for M1(pirenzepine), M2(methoctramine)and M3(darifenadn)muscarinic receptor subtypes.The sensitivity to PTX was tested by the ip injection of 100 mg/kg of PTX 5 d before the experiment.The antral circular smooth muscles were removed from PTX-treated and non-treated rats as strips and dispersed smooth muscle cells to identify whether PTX-linked pathway mediated the contractility to bethanechol. RESULTS:A dose-dependent contractile response observed with bethanechol,was not affected by TTx.The pretreatment of rats with pertussis toxin decreased the contraction induced by bethanechol.Lack of calcium as well as the presence of the L-type calcium channel blocker,nifedipine,also inhibited the cholinergic contraction,with a reduction in response from 2.5±0.4 g/mm^2 to 1.2±0.4 g/mm^2(P<0.05).The dose- response curves were shifted to the right by muscarinic antagonists in the following order of affinity:darifenacin (M_3)>methocramine(M_2)>pirenzepine(M_1). CONCLUSION:The muscarinic receptors-dependent contraction of rat antral circular smooth muscles was linked to the signal transduction pathway(s)involving pertussis-toxin sensitive GTP-binding proteins and to extracellular calcium via L-type voltage gated calcium channels.The presence of the residual contractile response after the treatment with nifedipine,suggests that an additional pathway could mediate the cholinergic contraction.The involvement of more than one muscarinic receptor(functionally predominant type 3 over type 2)also suggests more than one pathway mediating the cholinergic contraction in rat antrum.

Study of the duodenal contractile activity during antral contractions

AIM： To investigate the hypothesis that duodenal bulb （DB） inhibition on pyloric antrum （PA） contraction is reflex. METHODS： Balloon （condom）-tipped tube was introduced into 1^st duodenum （DD） and a manometric tube into each of PA and DD. Duodenal and antral pressure response to duodenal and then PA balloon distension with saline was recorded. These tests were repeated after separate anesthetization of DD and PA. RESULTS： Two and 4 mL of 1^st DD balloon distension produced no pressure changes in DD or PA （10.7±1.2 vs 9.8±1.2, 11.2±1.2 vs 11.3±1.2 on H20 respectively, P〉0.05）. Six mL distension effected 1^st DD pressure rise （30.6±3.4 cm H20, P 〈0.01） and PA pressure decrease （6.2±1.4 cm H20, P〈0.05）; no response in 2^nd, 3^rd and 4^th DD. There was no difference between 6, 8, and 10 mL distensions. Ten mL PA distension produced no PA or 1^st DD pressure changes （P〉 0.05）. Twenty mL distension increased PA pressure （92.4 4±10.7 cm H20, P〈0.01） and decreased 1^st DD pressure （1.6±0.3 cm H20, P〈0.01）; 30, 40, and 50 mL distension produced the same effect as the 20 mL distension （P 〉 0.05）. PA or DD distension after separate anesthetization produced no significant pressure changes in PA or DD. CONCLUSION： Large volume DD distension produced DD pressure rise denoting DD contraction and PA pressure decline denoting PA relaxation. PA relaxation upon DD contraction is postulated to be mediated through a reflex which we call duodeno-antral reflex. Meanwhile, PA distension effected DD relaxation which we suggest to be reflex and termed antro-duodenal reflex. It is suggested that these 2 reflexes, could act as investigative tools in diagnosis of gastroduodenal motility disorders.