Effects of Infrasound on Gastric Motility, Gastric Morphology and Expression of Nitric Oxide Synthase in Rat.

Infrasound widely exists in nature, our living condition, productive and traffic environment. Gastrointestinal tract is relatively sensitive to infrasound. However, the effect of infrasound on gastrointestinal function is unclear. Therefore, the purpose of our study was to observe the effects of infrasound on gastric motility and gastric morphology and to assess the expression of nitric oxide synthase (NOS) in gastric antrum after exposure to infrasound of 8 Hz - 130 dB for 2 hours per day for 14 consecutive days. Gastric motility was assessed by gastric fluid-emptying rate. Gastric morphology was evaluated by HE. The expression of NOS was measured by tissue microarray technology. The results would contribute to understand the role of infrasound in gastroenterology, and help to explain the mechanism of infrasound on gastroenterology.

Portulacaoleraceal extract alleviates trinitrobenzene sulfonic acid-induced colitis in rats.

Portulacaoleraceal (POL) has been widely used as an edible plant and a folk medicine in many countries, due to its several health benefits. This study examined the effects of POL on trinitrobenzene sulfonic acid (TNBS)-induced colitis via enema administration. Sixty male Sprague-Dawley rats were randomly divided into five groups: untreated, TNBS, TNBS + POL 10 g/kg, TNBS + POL 5 g/kg and TNBS + POL 2.5 g/kg groups. Rats were subjected to enema treatment once a day for 10 consecutive days with POL extract or distilled water after induction of TNBS. The changes of body weight, histological parameters, myeloperoxidase (MPO), superoxide dismutase (SOD), nitric oxide synthase activity (NOS), malondialdehyde (MDA) and nitric oxide (NO) levels in colon tissues were investigated. After POL extract treatment, body weights of rats significantly increased, macroscopic and microscopic damage scores reduced, MPO and NOS activity, as well as MDA and NO level significantly decreased, while SOD activity increased in a dose-dependent manner in the TNBS + POL groups compared with the TNBS group. Our results demonstrated that POL enema treatment attenuated pathologic changes of TNBS-induced colitis in rats through restoring colonic damage and reducing inflammatory response in the intestine. Thus, POL enema might be considered as a potential effective treatment for ulcerative colitis patients.

The expression of protease-activated receptor 2 and 4 in the colon of irritable bowel syndrome patients.

BACKGROUND: Irritable bowel syndrome (IBS) pathophysiology has not been fully understood. Abnormalities of serine proteases have been identified in IBS patients. In addition, protease-activated receptors (PAR) activation interferes with several components of the pathogenesis of IBS, so, evaluating the PAR expression in IBS patients may contribute to understanding the pathogenesis of the disease. AIMS: This study aimed to investigate whether the expression of PAR4 and PAR2 in the colon was changed in IBS patients and was associated with IBS. METHODS: Colon mucosal biopsies of 34 IBS patients (16 constipation- and 18 diarrhea-predominant) and 18 control subjects were collected. Gene transcripts of PAR2, PAR4, tryptase, and trypsin were quantified using real-time polymerase chain reaction (PCR) and the expression of PAR2 and PAR4 receptors was also measured by immunohistology and image analysis. RESULTS: In IBS patients, the mRNA expression of tryptase and trypsin normalized against ß-actin gene was higher compared to control subjects (P < 0.001). No difference was observed in the PAR2 mRNA level or protein level between control subjects on the one hand and IBS patients or subgroups on the other. In IBS or IBS subgroups patients, the expression of PAR4 in the mRNA level or protein level was lower than the control subjects. CONCLUSIONS: This study, for the first time, indicated the PAR4 expression in IBS patients. Decreased PAR4 expression may help us to understand the pathogenesis of IBS.

[Small intestine motility and gastrointestinal hormone levels in irritable bowel syndrome].

OBJECTIVE: To investigate the relationship between interdigestive migrating motor complex (MMC) and plasma gastrointestinal hormones in patients with diarrhea or constipation-predominant irritable bowel syndrome (IBS) to elucidate the pathophysiology of IBS. METHODS: A small intestine manometry was used to record the MMC cycles for at least 4-6 h in 19 IBS patients and 10 healthy volunteers. The plasma gastrointestinal hormone levels were examined according to altered MMC phases. RESULTS: Compared with the healthy controls, IBS-D patients exhibited shortened duration of the small intestinal MMC cycle, prolonged phase III duration with greater amplitude, as well as faster propagation velocity, whereas the contrary alterations were found in IBS-C patients. The peak plasma motilin level occurred in phase III of the MMC cycle. The plasma somatostatin level was higher in IBS groups than in the healthy controls, but comparable between the diarrhea and constipation groups. Plasma 5-hydroxytryptamine showed periodical fluctuations with the phases of MMC cycles, reaching the peak level in phase II. IBS-D patients had higher 5-hydroxytryptamine levels than IBS-C patients and the healthy controls. CONCLUSIONS: Plasma hormone levels are correlated with the MMC cycles, and the hormone level changes and small intestine motility disorder may play important roles in IBS pathophysiology.