The bradykinin BK2 receptor mediates angiotensin II receptor type 2 stimulated rat duodenal mucosal alkaline secretion

BACKGROUND: This study investigates bradykinin and nitric oxide as potential mediators of AT2-receptor-stimulated duodenal mucosal alkaline secretion. Duodenal mucosal alkaline secretion was measured in methohexital- and α-chloralose-anaesthetised rats by means of in situ pH-stat titration. Immunohistochemistry and Western blot were used to identify the BK2 receptors. RESULTS: The AT2 receptor agonist CGP42112A (0.1 μg kg(-1 )min(-1)) administered intravenously increased the duodenal mucosal alkaline secretion by ~50 %. This increase was sensitive to the selective BK2 receptor blocker HOE140 (100 ng/kg iv), but not to luminal administration of the NOS blocker L-NAME (0.3 mM). Mean arterial pressure did not differ between groups during the procedures. Immunohistochemistry showed a distinct staining of the crypt epithelium and a moderate staining of basal cytoplasm in villus enterocytes. CONCLUSION: The results suggest that the AT2-receptor-stimulated alkaline secretion is mediated via BK2 receptors located in the duodenal cryptal mucosal epithelium

Distribution of Selected Heavy Metals in Sediment of the River Basin of Coastal Area of Chanthaburi Province, Gulf of Thailand

The sediment samples from 24 stations in coastal area of Chanthaburi Province were collected during March 2012 to March 2013 and analyzed for heavy metal contents (Pb, Cd, Cr, Fe, Cu and Zn), pH, organic matters and grain sizes. The correlation analyses showed that heavy metal concentrations were affected by the content of organic matter and the size of clay particles. The evaluation of the quality of sediment was carried out using the geoaccumulation index (Igeo) and the enrichment factor (EF) as well as the comparison with those in the Thailand's sediment quality guideline (SQG) values. The results of the geoaccumulation index and the enrichment factor values of the heavy metals content in the sediments revealed that the study area was unpolluted and not enriched, respectively. The relationship between the heavy metals concentration and the organic matter, and the clay particle was proposed by using the multiple regression equations

Angiotensin II receptor expression and relation to Helicobacter pylori-infection in the stomach of the Mongolian gerbil

<p>Abstract</p> <p>Background</p> <p>The role of the renin-angiotensin system in gastric physiology and disease has as yet been sparsely explored. The first aim of the study was to investigate the baseline presence and location of angiotensin II receptors (AT1R and AT2R) in the stomach of the Mongolian gerbil. A second aim was to elucidate whether the presence of <it>H. pylori </it>infection is associated with changes in the expression of these receptors.</p> <p>Methods</p> <p><it>H. pylori</it>-negative and <it>H. pylori-</it>infected (strain SS1 or TN2GF4) male Mongolian gerbils were investigated. The stomachs were examined at six or 12 months after inoculation by the use of immunohistochemistry, western blot and microscopic morphometry.</p> <p>Results</p> <p>AT1R and AT2R were located in a variety of cells in the gerbil gastric wall, including a subpopulation of endocrine cells in the antral mucosa and inflammatory cells infiltrating <it>H. pylori</it>-infected stomachs. Gerbils infected with the SS1 strain showed a significantly increased antral AT1R protein expression and an increased number of infiltrating polymorphonuclear leucocytes (PMNs) at 12 months. The AT1R protein expression correlated with the number of PMNs and the antral expression of myeloperoxidase.</p> <p>Conclusions</p> <p>Angiotensin II receptors are present in a variety of cells in the gastric wall of the Mongolian gerbil. The results indicate an influence dependent on the <it>H. pylori </it>strain on the gastric AT1R expression and a relationship between gastric AT1R expression and mucosal PMNs infiltration.</p

Asymmetric mucosal structure, mesenteric versus antimesenteric, in mouse, rat, and human small intestines

Abstract The morphology of the small intestinal mucosa is reflected by the degree of stimuli. Previous studies have come to different conclusion about whether the mucosa is equally symmetrical. The aim of the study is to investigate whether there are structural differences in the mesenteric versus antimesenteric mucosa in mice, rats, and humans. Jejunal biopsies from mice and rats were saved. Samples from human small intestine were obtained from patients undergoing Roux‐en‐Y gastric bypass surgery. Fixed samples were used to morphologically evaluate villus height and enlargement factor due to villi. The number of goblet cells, mast cells, enteroendocrine cells, and Paneth cells were histologically analyzed in the villus structure. Cell turnover was analyzed by Ki‐67 staining. There was a significant increased villi height and villus enlargement factor antimesenterically in mice, rats, and human small intestines. The distribution of goblet cells, mast cells, and Paneth cells were equal while the number of enteroendocrine cells was increased antimesenteric in the human samples. The crypt mitotic activity was almost 20% higher in the antimesenteric part of jejunum. In summary we found longer villi, greater surface enlargement, and increased number of enteroendocrine cells as well as increased cell turnover antimesenterically. These differences may be of importance in understanding normal gastrointestinal physiology in health and disease

Health Risk Assessment and DNA Damage of Volatile Organic Compounds in Car Painting Houses

Car painters who work near volatile organic compounds (VOCs) sources, including paints, solvents and painting processes may be exposed to highly elevated VOCs levels. This study investigates air samples from car painting houses in Thailand to evaluate the health risks following inhalation exposure. Personal air samplings were obtained at nine garages in Phitsanulok, Thailand from June to September 2012. The concentrations of benzene, toluene, ethylbenzene, xylenes, and styrene in the air workplaces were significantly higher than in a control group of office workers (p < 0.05). Toluene, xylene and ethylbenzene were the most abundant species. However, all VOCs in these air samples were lower than TWA limit of Thailand and the OSHA standard. The lifetime cancer and non-cancer risks for the workers exposed to VOCs were also assessed. The average lifetime cancer risk was 41.0 (38.2-47.2) per million, which is in the acceptable risk. The average lifetime non-cancer risk, the HI, was 0.962 (0.643-1.397), which is well below the reference hazard level. Urine samples, collected after 8-h work periods which were analyzed for VOCs metabolites, including t,t muconic acid, hippuric acid, mandelic acid and m-hippuric acid, demonstrate that the average levels of metabolites in car painters and in controls were close. All VOCs metabolites in urine samples were lower than BEI of ACGIH standard. Blood samples, collected after 8-h work periods which were analyzed by single cell gel electrophoresis (comet) assay. The DNA damage, assessed by tail moment, demonstrates that the average of tail moment in car painters were significantly higher than in the controls (p < 0.05)