1.Effect of vincristine on the myoelectric activity and motility of the small intestine in rats
Lei WANG ; Hui ZHOU ; Tao ZHAO ; Wei ZHANG ; Zhaoshen LI ; Jun GAO
Chinese Journal of Digestion 2008;28(9):604-607
Objective To investigate the effects of vincristine on myoelectric activity and motility of the small intestine in conscious rats and its mechanism. Methods Seventy-two SD rats were divided into six groups. The rats in control group were received 0.9% NaCl solution (n=18). The rats in group B were injected with vincristine and subdivided into 0.25 mg/kg(n=6) ,0.5 mg/kg(n=6)and 0.75 mg/kg groups. The group C and D was false operation (n=6)and false operation plus injection with 0.75 mg/kg of vincristine(n=6), respectively. The group E and F was subdiaphragmatic vagotomy plus 0.9% NaCl (n=6) or subdiaphragmatic vagotomy plus 0.75 mg/kg of vincristine (n=6), respectively. The myoelectric activity and motility of the small intestine were recorded. The frequency and area under the curve of slow wave, the periodicity of the migrating myoelectrie complex (MMC) and the duration of MMC Ⅲ were analyzed. The expressions of the myenteric neurons and interstitial cells of Cajal were evaluated by immunofluorescence stain. Results The myoelectric activity in 0.25mg/kg group was not different from the controls, but it changed in 0.5 mg/kg and 0.75 mg/kg groups which correlated with the time of vincristine injection. The irregular spike activity arose and accompanied with disruption of the MMC at (51±14.27) minutes,but recovered at (78.33±13.08) minutes. The periodicity was shorter in 0.5mg/kg [(343.17±142.93)s]and 0.75 mg/kg groups [(302.67±66.67)s] compared with controls [(740.22± 98.92) s, F=31.325, P<0.01]. Three days after vincristine administration, the area under the curve of slow wave decreased to (2.56±0.30) mV·s in 0.5 mg/kg group and (2.57±0.56) mV·s in 0.75 mg/kg group compared with the controls ((4.10±0.80) mV·s , F = 11.442, P<0.01). The intestinal propulsive rate was lower in 0.75 mg/kg group compared with the controls [(33.59±1.43) vs(60.34±2.41)%,t= 23.36, P<0.01]. The expression of the interstitial cells of Cajal was less than those in controls. Three days later, the area under the curve of slow wave in F group was less than that in controls. Conclusions Vincristine provokes alterations of myoelectric activity and motility of the small intestine. The early vincristine-induced escalating in myoelctric activity of the small intestine is through vagus nerve pathway. The decreased motility is contributed to the damage of the interstitial cells of Cajal.
2.The enhancement effect of domperidene on esophagus and lower esophageal sphincter
Lu ZHOU ; Lijian WANG ; Bo YUANG ; Hang ZHANG
Chinese Journal of Digestion 2008;28(9):594-599
Objective To observe the prokinetic effect of domperidone on esophagus and lower esophageal sphincter (LES), and compare its effect with that of mosapride and cisapride. Methods In vivo experiments: forty rats were divided into control, domperidone, mosapride, and eisapride groups. Strain gauges were planted in proximal esophagus, distal esophagus and LES to record the activities of esophagus and LES in conscious rat. In vitro experiments: in the thermostatic muscle bath, the prokinetic effect of domperidone, mosapride, and cisapride on the contractility of rat muscle strips from esophagus body and LES were recorded by tone-transducers. Results In vivo experiments, ① In the interdigestive period of resting conscious rats, only mild contraction activities were recoded in esophagus bodies. In LES, typical interdigestive migrating motor complex (MMC) with phase Ⅰ,Ⅱ,Ⅲ,and Ⅳ was recorded. The contraction amplitude of LES was much greater than esophagus body. ② Domperidone significantly enhanced the contraction of esophagus body and LES. The mean contraction amplitude of proximal esophagus, distal esophagus, and LES increased by 63.24%±7.17%, 75.54%±5.27%, and 85.81%±6.02%, respectively, compared with controls. The prokinetic effect showed a dose-effect relation. Mosapride at the same dosage increased the mean contraction amplitude of proximal esophagus, distal esophagus, and LES by 29. 71%±4.15%, 40.15%±3.30%, and 35.24%±5.36%, respectively, compared with controls. The prokinetic effects of mosapride on esophagus and LES were much less than domperidone. Cisapride at the same dosage increased the mean contraction amplitude of proximal esophagus, distal esophagus, and LES by 59.84%±6.55%, 70.11%±5.62%, and 75.13%± 5.10%, respectively, compared with controls. The prokinetic effects of cisapride were similar as domperidone. In vitro experiments. ① Domperidone perfusion could significantly increase the contraction of esophagus body and LES muscle strips by 87.74%±7.65% and 92.44±7.17%, respectively, compared with Krebs-Ringer (KR) solution perfuslon. Mosapride at the same dosage increased the mean contraction amplitude by 35.42%±5.02% and 31.12%±4.32%, respectively, compared with KR controls. The prokinetic effects of mosapride were much less than domperidone. Cisapride of the same dosage showed a similar prokinetic effect as domperidone. ② Atropine and tetrodotoxin could block the prokinetic effects of domperidone on esophagus and LES. Conclusions Domperidone can significantly enhance the esophagus body contraction and LES motility. The effects of domperidone are similar as cisapride and much greater than mosapride. The prokinetic effects of domperidone on esophagus and LES are not only through well-known dopaminergic receptor blockade, but also through the cholinergic nerves of the enteric nervous system.
3.The prevention of epigallocatechin gallate on colon preneoplastic lesion
Junhua YUAN ; Yanqing LI ; Xiaoyun YANG
Chinese Journal of Digestion 2008;28(9):590-593
Objective To investigate wheter epigallocatechin gallate (EGCG) could prevent the information of abrant crypt loci (ACF) induced by isoquinoline (IQ)and its possible mechanisms. Methods Sixty male BALB/cA nude immunological deficit mice were divided into five groups. Except control group, the other four groups were received IQ to induce ACF. The rats in low, medium and high dose groups were received 5, 10 and 20 mg/kg of EGCG,respectively. The mice were sacrificed six weeks later. Hematoxylin-eosin (HE) staining and 0.2% methylene blue staining were used to observe the routine histology and ACF, respectively. Immunohistochemistry (IHC) was used to detect Nrf2 protein level and RT-PCR was used to detect Nrf2 and UGT1A10 mRNA levels in colon tissue. Results The body weights of model group decreased significantly compared to high-dose group (21.70±0.13 vs. 24.37±0.07, P<0.01). Compared to model group, the degree of atypical hyperplasia and even canceration of colon mucus and the number of total ACF and total AC in high-dose group were decreased significantly (18.00±7.51 vs. 64.20±45.18, P<0.05;63.90±18.58 vs. 168. 80±35.34, P<0.01). The protein level of Nrf2 increased (0.3114±0.0037 vs. 0.1660±0.0021, P<0.01). The mRNA levels of Nrf2 and UGT1A10 in high-dose group was increased (both P value<0.01). Conclusions EGCG has protective effect on IQ induced preneoplastic lesions through reducing the number of ACF. This effect may be caused partly through the signal pathway Nrf2-UGT1A10.
4.Proteomic analysis of pancreatic cancer associated with diabetes mellitus
Lin ZHOU ; Weiyan YAO ; Lishun WANG ; Jiangcheng WANG ; Guoqiang CHEN ; Yaozong YUANG
Chinese Journal of Digestion 2008;28(10):699-701
Objective To identify the different proteins of pancreatic cancer with and without diabetes mellitus (DM) ,so as to provide some clues for understanding the molecular mechanisms of DM in the development .of pancreatic cancer. Methods Samples were divided into pancreatic cancer with or without DM and their normal adjacent tissue with 5 each. The protein expression profiles were analyzed using 2-DE in combination with MALDI-TOF/TOF MS/MS. Western blot was used to verify the expression of a candidate protein CapG. Results Seven proteins were obviously up-regulated in pancreatic cancer with DM(P<0.05). These proteins were involved in cell motility, metabolism, oxidative stress, etc. Additionally, CapG implicated a functional contribution of cancer invasion and metastasis. Conclusion The results also provide evidence to support the hypothesis that DM plays an important role in the development of pancreatic cancer.
5.Changes of serum C-reactive protein in patients with Crohn's disease
Beibei WANG ; Xiang GAO ; Minhu CHEN ; Li YANG ; Fangbin ZHANG ; Pinjin HU
Chinese Journal of Digestion 2008;28(10):686-689
Objective To compare the changes of serum C reactive protein (CRP) in different lesion site and activity so as to evaluate its worthy of an indicator of disease activity. Methods Forty-two patients with Crohn's disease (CD) were divided into small intestinal group and colonic group according to the involved lesions. Twenty-three cases of UC and 26 cases of inflammatory bowel disease (IBS)were served as controls. The serum level of hs-CRP was tested using latex-enhanced immunoturbidimetery. mg/L and (1.1±1.8)mg/L, respectively. Hs-CRP was elevated significantly in CD group compared to UC and IBS groups (P<0.001). The ratio of patients whose hs-CRP exceeded 3 mg/L was 76.2%, 30.4% and 7.7% in CD, UC and IBS, respectively (P=0.000). The ratio was significantly higher in CD higher than that of small intestinal group [(11.9±7.6 )mg/L vs (6.8±7.2)rag/L, P =0.04]. The ratio of patients whose hs-CRP exceeded normal value was higher in colonic group than that in small CRP(≥10 rag/L). Among them, 4/17 were in remission, 3/11 in mild, 10/13 in moderate and 1/1 in severe according to the CDAI. The hs-CRP was correlated well with CDAI and ESR (r was 0.52 and 0.70 respectively, P<0.001). Conclusions CRP can he used as a inflammatory marker for evaluating the disease activity of CD. The patients with small intestinal involvment may have lower CRP than those with colonic affection. The elevation of CRP was paralleled to the disease severity of CD.
6.The promoter methylation of death-associated protein kinase influences expressions of its mRNA and protein in tissue of gastric cancer
Mei YE ; Bing XIA ; Dongqing LI ; Feng ZHOU ; Qiusha GUO
Chinese Journal of Digestion 2008;28(10):678-681
Objective To investigate the regulation effect of promoter methylation of deathassociated protein kinase (DAPK) on mRNA and protein expression of DAPK in tissue of primary gastric cancer (GC). Methods The cancerous and noncancerous samples from 62 patients with GC were determined by RT-PCR for mRNA expression of DAPK. The DAPK promoter methylation was detected by methylation-specific PCR. The protein expression of DAPK in 34 patients with methylation was determined by Western blot. Results mRNA and protein expre.ssions of DAPK in cancerous tissues were reduced significantly compared to noncancerous tissues (0. 2863d±0. 2027 vs 0. 57364±0. 1968,0. 2616±0. 0913 vs 0. 65294±0. 1808, P<0.01). Methylation frequency of DAPK in cancerous tissues was higher than that in noncancerous tissues (54.8% vs 17.7%, P<0.01). Furthermore, DAPK mRNA expression was decreased in methylation group compared to unmethylation group (0.1399±0. 0835 vs 0. 46404±0. 1569, P<0. 01). Moreover, a significant correlation was demonstrated between the TNM stage and DAPK promoter methylation (P = 0. 04). Conclusion Expression of DAPK is down-regulated in cancerous tissues at mRNA and protein levels. Low expression of DAPK is associated with hypermethylation of the promoter of DAPK gene.
7.The role of pituitary adenylate cyclase-activating polypeptide in the growth modulation of human pancreas carcinoma
Min ZHAO ; Ruolan JIANG ; Lumei SUN
Chinese Journal of Digestion 2001;21(2):86-89
Objective To investigate the role pituitary adenylate cyclase-activating polypeptide (PACAP) in the growth modulation of PACAP of human pancreas carcinoma cells and determine whether sphingomyolin (SM) may act as a second messenger involved in the postreceptor signal transduction. Methods Human pancreas carcinoma cell strains, JF305, HS766T and ASPC-1 cells were cultivated, reproduced and then treated with PACAP1-38 (10- 12 - 10- 6 M). The amounts of proliferated carcinoma cells were estiimated with Mosmann's method (MTT). The concentrations of intracellular SM in cells were determined with thin layer chromotograph. Intracellular adenosine monophosphate and Ca2 + levels were detected by radioimmunoassay and Fura-2/AM respectively. ResultsIt was found that three kind of human pancreatic cancer cells were proliferated and the intracellular levels of SM, cAMP and cytosolic Ca2+ were increased by treating PACAP1-38. The effect of PACAP1-38 in JF305, HS766T and ASPC-1 could be inhibited by Somatostatin.ConclusionPACAP1-38 may play a role in the proliferation of human pancreatic cancer cells. The postreceptorsignal transduction of PACAP may be mediated by both adenosine cyclinase and Calcium-calmodin pathways. SM may be a second messenger involved in this process.
8.The effects of pioglitazone on the process of oxidative stress in acute pancreatitis induced by cerulein
Chinese Journal of Digestion 2008;28(8):531-534
Objective To investigate the effects of pioglitazone,a peroxisome proliferation activated receptor(PPAR)γ agonist on oxidative stress process and the therapeutic effects on severity of acute pancreatitis(AP).Methods Thirty male Sprague-Dawley rats were randomly divided into five groups with 6 in each:control group,eerulein plus pioglitazone group,cerulein group,cerulein plus vehicle group,cerulein plus pioglitazone and GW9662 group.Rats were sacrificed at 30 min after the induction of pancreatitis.Pathologic changes of the pancreas were observed under light microscope.The ratios of pancreatic wet/body weight of rat were determined in each group.Serum amylase,pancreatic nitric oxide synthase(NOS),inducible nitric oxide synthase(iNOS),malondialdehyde(MDA),and myeloperoxidase (MPO)were determined by chromometry.Results The serum amylase,pancreatic wet/body weight and the score of pathologic damage increased after the induction of pancreatitis,AP samples were characterized by increased pancreatic MDA,MPO,NOS and iNOS(P<0.01).Pioglitazone(20 mg/kg and 40 mg/kg)exhibited a protective effect against oxygen free radicals reflected by lower serum amylase,less severe pancreatic lesions,normal pancreatic MDA,MPO and NOS levels(P<0.05).GW9662 reversed the effects against oxidative stress of pioglitazone(40 mg/kg)(P<0.05).Conclusions Pretreatment with pioglitazone may exert its therapeutic effect on AP by lowering pancreatic oxidative free radicals and reducing pancreatic tissue infiltration of neutrophils.
9.Role of NR2B in estrogen increasing visceral hypersensitivity of female stressed rats
Junkai SU ; Jun GAO ; Zhaoshen LI ; Duowu ZOU ; Hailian CAO
Chinese Journal of Digestion 2008;28(8):527-530
Objective As estrogen increases visceral hypersensitivity induced by water avoidance stress in female rats,further experiment was designed to determine whether the influence of estrogen involves NR2B.Methods Healthy adult female Wistar rats were bilaterally ovariectomized,and then housed individually.Implantation of cannula into lateral cerebroventricle and electrodes into the abdominal muscle had been done.After 5 days recovery,rats with abnormal behavior and ehctromyography were excluded,finally a total of 48 rats were eligible,and were equipped for abdominal muscle electromyography and submitted to water avoidance stress(WAS).Visceromotor response(VMR)to 20,40,60 and 80 mmHg colorectal distension(CRD)was recorded in rats intracerebroventricular-infused with either 17β-estradiol,normal saline,AP5(NMDA receptor-antagonist)or Ro25-6981(NR2B antagonist).NR2B mRNA in anterior cingulate cortex or dorsal root ganglia were compared by real-time PCR between the rats treated with 17β-estradioI and that with normal saline.Results Bilaterally ovarieetomized rats treated with 17β-estradiol,exhibited more visceral hypersensitivity after WAS than that with normal saline on 40,60 and 80 mmHg CRD(P=0.039,P=0.033,P=O.001).The VMR on 40 and 60 mmHg CRD in 17β-estradiol treated group was not significantly different from that in 17β-estradiol plus Ro25-6981 treated group.Whilst,significant differences of VMR were noted between 17β-estradiol treated group and 17β-estradiol plus Ro25-6981 treated group on 80 mmHg CRD,17β-estradiol treated group and 17β-estradiol plus AP5 treated group on 60,80 nmmHg CRD,respectively.17β-estradiol increased NR2BmRNA in anterior cingulate cortex(0.57±0.41 vs 0.21±0.13,P=0.048),but not in dorsal root ganglia(0.35±0.45 vs 0.38±0.31,P=0.465). Stress-induced visceral hypersensitivity in the hormonally-restored visceral hyper-responsiveness of bilaterally ovariectomized rats was antagonized by AP5 or Ro25-6981.Conclusions Estrogen may be mediated through NR2B activation to enhance visceral sensitivity in female stressed rats,that probably related with the increased expression of NR2B mRNA in anterior cingulate cortex.
10.Quantificational assessment of classification of liver cirrhosis in patients with hepatocellular carcinoma by multi-slice spiral CT perfusion imaging
Jianlun LIU ; Danke SU ; Caihong WANG ; Xiaoyan ZHOU ; Qiang LI
Chinese Journal of Digestion 2008;28(8):517-521
Objective To measure hepatic blood flow of the normal liver and cirrhotic liver with hepatocellular carcinoma using multi-slice spiral CT(MSCT),and to evaluate the feasibility of the quantitative judgement of classification of liver cirrhosis with CT perfusion imaging.Methods CT dynamic perfusion imaging was performed in 53 subjects,including 32 patients of liver cirrhosis with hepatocellular carcinoma and 21 patients without liver disease(control subjects).The patients of liver cirrhosis with hepatocellular carcinoma were divided into three groups by CT morphologic classification :17 were classified as light liver cirrhosis group,8 as moderate group,7 as severe group.The parameters of CT perfusion included blood flow(BF),blood volume(BV),mean transit time(MTT),hepatic arterial fraction(HAF)and impulse residue function to(IRF To).The parameters were analyzed by the CT perfusion 3 software package(GE)with deconvolution method,and the correlation of the CT morphologic classification of liver cirrhosis with Child-Pugh functional classification was further evaluated.100 g-1,(17.81±6.59)ml/100 g,(9.52±3.08)s,0.20±0.08 and(4.38±2.35)s,respectively,while 0.27±0. 09 and (4. 14±2. 16)s, respectively. The mean BF, BV and HAF between normal livers and liver cirrhosis were statistically significant (P<0. 05), and there were significant statistical differences in BF, BV and HAF among light, moderate and severe liver cirrhosis (P<0. 05). The CT morphologic classification of liver cirrhosis was correlated positively with Child-Pugh classification (r=0. 935, P=0. 001 ). Conclusions Hepatic perfusion with MSCT can reflect the change of blood flow of cirrhotic liver, and MSCT perfusion can quantitatively evaluate the liver cirrhosis degree of patients with hepatocellular carcinoma.