Objective To study the changes of intestinal transit rate, quantity of enterochromaffin cells and expressions of 5-hydroxytryptamine receptor 3 (5-HT3R) in SD rats at different ages, and to investigate the possible mechanism of gastrointestinal dysfunction in aged rats. Methods Eighty healthy SD rats were divided into five groups: three months age, nine months age, eighteen months age, twenty-four months age and thirty months age,and there were sixteen rats in each group. The intestinal transit rate was detected. Immunohistochemistry staining was used to test the quality of chromaffin cells in mucosa and submucosa of jejunum, ileum and colon and to detect the expressions of 5-HT3R in intestinal myenteric plexus. Results The intestinal transit rate was significantly lower in thirty months age group than in three months age group [(52.1±9.8)% vs. (67.2±13.5)%, t=7.013, P=0.001]. In thirty months age group, the quality of chromaffin cells in mucosa and submueosa of jejunum, ileum and colon were 11.1±3.0, 10.6±1.9, 10.2±4.3, respectively, which were reduced compared with three months age group (22.9±6.2, 25.8±7.1, 23.0±5.7, t=3. 640,3. 384,4. 154, all P<0.01). The expressions of 5-HT3R in myenteric plexus of jejunum and ileum were reduced in thirty months age group than in nine months age group [4.8±1.4, 9.3±4.2 vs. 8.9±1.5, 14.5±5.3;t=3.464, 3.003,all P<0.01]. The expression of 5-HT3R in colon myenteric plexus were 5.0±1.3 and 9.0±1.7 in thirty months age group and three months age group, respectively (t=4.549,P<0.001). Conclusions In aged rats, the intestinal transit rate, quantity of enterochromaffin cells and expressions of 5-HT3R are decreased with ageing, and the gastrointestinal dysfunction may be associated with the changing of the quantity of enterochromaffin cells and expressions of 5-HT3R in myenteric plexus.

Objective To investigate the expression and distribution of 5-hydroxytryptamine 7(5-HT7)receptor in brain and intestine of rats with different subtype of irritable bowel syndrome(IBS).Methods Forty-five SD rats were divided into healthy contral.diarrhea-predominant(IBS-D)and consti pation-predominant(IBS-C)IBS groups.IBS-D and IBS-C models were established by either colonic instillation of acetic acid and restraint stress or stomach irrigation with cool water(0-4℃).The expression and distribution of 5-HT7 receptor at brain and intestine were determined by immunohistochemistry and real-time PCR.The tissue concentration of cyclic AMP(cAMP)was examined by radioimmunoassay.Results Immunohistochemistry study demonstrated that the staining of 5-HT7 receptor at hippocampus and hypothalamus were strong in IBS-C and IBS-D groups compared to control group(P＜0.01),The staining of 5-HT7 receptor at ileum,proximal colon and distal colon were higher in IBS-C group than those in control group(P＜0.05).Real-time PCR revealed that the expression of 5-HT7 receptor at hippocampus and hypothalamus were higher in IBS-C and IBS-D groups than those in control group(P＜0.05).and the expression at ileum and colon were remarkably higher in IBS-C group compared to control group(P＜0.05).The concentration of cAMP at hippocampus and hypothalamus were higher in IBS-C and IBS-D groups than those in control group(P＜0.01,P＜0.05).The cAMP level at proximal and distal colon in IBS-C group was higher than those in control group(P＜0.05).Conclusion The upregulation of 5-HT7 receptor in brain and intestine may be related with the dyskinesis and visceral paresthesia of IBS-C.

Objective: To analyze the clinicopathological and biological characteristics of esophageal submucosal tumors (SMTs) and to investigate the safety and efficacy of endoscopic resection for esophageal SMTs. Methods: We retrospectively analyzed the data of 152 cases of esophageal submucosal tumors resected by endoscopy in Department of Gastroenterology, The Second Affiliated Hospital of Xi'an Jiaotong University, from February 2013 to June 2018 as well as the pathological properties, distribution characteristics, origin and location of the esophageal SMTs. We also analyzed complications and efficacy of different methods for endoscopic resection. Results: The average age of onset of esophageal SMTs in this group was 52.74±10.53 years, without gender difference. Pathological features were as follows: leiomyoma was more common (73.68%), followed by stromal tumor (11.18%), hemangioma (3.95%), cyst (3.29%), and lipoma (1.97%). SMTs occurred mostly in the middle and lower segments of the esophagus. They were mainly located in the muscularis mucosa (31.58%) and muscularis propria (57.89%), and partly located in the submucosa (10.53%). Endoscopic resection methods consisted of endoscopic mucosal resection (EMR) performed in 36 cases, endoscopic submucosal dissection (ESD) in 52 cases, submucosal tunneling endoscopic resection (STER) in 63 cases, and full-thickness resection (EFTR) in 1 case. All lesions were completely resected. EMR had small tumor resection and shorter operative time; ESD and STER showed large tumor resection and long operation time (P<0.05). There was no significant difference in the incidence of complications among the three types of resection (P>0.05). Complications were effectively controlled. No local recurrence or residual cases were found in postoperative follow-up. Conclusion: Adult onset of submucosal tumors of the esophagus, without gender difference, can occur in all segments of the esophagus, mostly from the mucosal muscularis and muscularis propria. Leiomyoma is common, followed by stromal tumor, spindle cell tumor, and hemangioma. Endoscopic resection depends on the lesion location, source and size, and endoscopic treatment is safe and effective.

Objectives To compare the migrating motor complex (MMC) in irritable bowel syndrome (IBS) patients with that in healthy controls. To explore whether discrete clustered contractions (DCC) are connected with abdominal pain in IBS patients. To improve the method of measuring gastroenteric motility (esp. jejunum). Methods By using 16-channel water-perfused catheter and manometry instruments, MMC in 16 cases of IBS with constipation (IBS-C), 18 cases of IBS with diarrhea (IBS-D) and 18 cases of healthy controls were monitored. Results The MMC durations of IBS-C and IBS-D patients were (127.5±25.5) min and (74.5±18.7) min, respectively. Comparision with those in the control group [(87.5±24.2) min]showed significant differences (P<0. 001). The contraction amplitudes of stage Ⅲ in different sites of IBS-C patients decreased significantly as compared with those in the controls [jejunum, (39.8±11.7) mm Hg vs. (61.1±14.1) mm Hg,P<0.001,1 mm Hg=0.133 kPa]. The propagation velocities of stage Ⅲ in different sites of IBS-C patients also decreased significantly as compared with those in the controls [jejunum, (1.8±0.9) cm/min vs. (2.6±0.8) cm/min,P<0.01].The contraction amplitudes of stage Ⅲ in different sites of IBS-D patients increased significantly as compared with those in the controls [jejunum, (69.7±20.5) mm Hg vs. (61.1±14.1) mm Hg, P<0.01]. The propagation velocities of stage Ⅲ in different sites of IBS-D patients also increased significantly as compared with those in the controls [jejunum, (4.1±2.5) cm/min vs. (2.6±0.8) cm/min, P < 0. 01]. DCC incidences of IBS-C and IBS-D were 87.5% and 88. 8%, respectively. Comperision with those in the normal group (83.3%) did not show significant difference (P>0.05). The prevalences of abnormal stage Ⅲ contractions (include disturbances and interferences of stage Ⅲ contractions) in IBS-C and IBS-D patients were 68.8% and 66. 7%, respectively; there were no significant differences between the two groups (P > 0. 05). However abnormal stage Ⅲ contractions did not exist in healthy controls. Conclusions (1) The MMC of IBS-C and IBS-D patients are changed, as compared with that in healthy people; this implies that small intestinal motility dysfunction is one of the pathogenetic factors of IBS. The abnormal stage Ⅲ contractions in jejunum may be a predominant change in IBS gastroenteric motility. (2) No apparent connection is found between DCC and pain in IBS. (3) By using 16-channel water-perfused catheter, we first carried out the method of monitoring jejunum contractions in China. Parameters of MMC in Chinese healthy people were investigated, esp. those of jejunum.

OBJECTIVETo observe the effect of gut protease activity on visceral hypersensitivity in rats with acute restraint stress.

METHODSSprague-Dawley rats were given 30, 100 or 300 mg/kg camostat mesilate (CM), a protease inhibitor, or saline intragastrically 30 min before acute restraint stress induced by wrapping the fore shoulders, upper forelimbs and thoracic trunk for 2 h. Visceral perception of the rats was quantified as the visceral motor response with an electromyography, and the rectal mucosa and feces protease activity and spinal c-fos expression were measured.

RESULTSCM dose-dependently reduced visceral sensitization elicited by rectal distension, but these doses did not completely inhibit stress-induced visceral sensitization. In normal rats, c-fos expression was found mainly in the superal spinal cord dorsal horn, and after the administration the CM, c-fos-positive cells decreased significantly in all dose groups (P<0.05). In 30 mg/kg CM group, fecal and rectal mucosal protease activity significantly decreased as compared with that in the stress group (P<0.05), and as CM dose increased to 100 and 300 mg/kg, the protease activity decreased even further (P<0.01).

CONCLUSIONThe gut protease is involved in acute stress-induced visceral hypersensitivity, and CM can lower the visceral sensitivity and spinal c-fos expression in rats.

Animals ; Gabexate ; analogs & derivatives ; pharmacology ; Protease Inhibitors ; pharmacology ; Proto-Oncogene Proteins c-fos ; metabolism ; Rats ; Rats, Sprague-Dawley ; Restraint, Physical ; Spinal Cord ; metabolism ; Stress, Physiological