Linc00852 from cisplatin-resistant gastric cancer cell-derived exosomes regulates COMMD7 to promote cisplatin resistance of recipient cells through microRNA-514a-5p.

OBJECTIVE: Cisplatin (DDP)-based chemotherapy is commonly referred to as advanced gastric cancer (GC). The purpose of this study was to unravel whether Linc00852 from DDP-resistant tumor cell-derived exosomes (Exos) promotes DDP resistance of GC cells. METHODS: Reverse transcription quantitative polymerase chain reaction was used to detect the expression of Linc00852, miR-514a-5p, COMM domain protein 7 (COMMD7) mRNA, Bax mRNA, and Bcl-2 mRNA. Western blot was used to measure the expression of COMMD7 protein. The IC50 value of DDP is determined by MTT assay. The cell proliferation ability was measured by colony formation test. The apoptosis ability was measured by flow cytometry. The interaction between Linc00852, miR-514a-5p, and COMMD7 was confirmed by luciferase reporter gene assay and RNA pull-down assay. Xenograft tumor model was used to study the effect of Linc00852 on DDP resistance in vivo. RESULTS: Linc00852 was up-regulated in DDP-resistant GC cells and their secreted exosomes. Down-regulating Linc00852 facilitated the sensitivity of DDP-resistant GC cells to DDP. Linc00852 bound to miR-514a-5p and COMMD7 was a target of miR-514a-5p. Linc00852 could regulate COMMD7 expression via targeting miR-514a-5p. Exosomes from DDP-resistant GC cells enhanced the resistance of recipient GC cells to DDP via exosomal delivery of Linc00852. Depletion of Linc00852 repressed the growth and DDP resistance of GC cells in vivo. CONCLUSION: Linc00852 from DDP-resistant tumor cell-derived Exos regulates COMMD7 to promote drug resistance of GC cells through miR-514a-5p.

DDX1 is a prognostic biomarker and correlates with immune infiltrations in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is one of the leading lethal malignant tumors worldwide. DEAD-box (DDX) family helicases are implicated in numerous human cancers. However, the role of DDX1 in HCC has not yet been fully elucidated. We downloaded gene expression data and clinical information data of HCC from The Cancer Genome Atlas and International Cancer Genome Consortium (ICGC) database and conducted subsequent analyses using the R package and online portal. The results revealed that HCC tissues had higher DDX1 expression compared with either paired or unpaired normal tissues. The increased DDX1 expression was closely related to the advanced pathological grade and histologic grade of HCC. Further analysis suggested that patients with high DDX1 expression contributed to poor prognosis The Cox regression analysis revealed that the expression level of DDX1 was an independent prognostic factor for HCC. In addition, an ICGC cohort was used for external validation. The cBio-Portal, MethSurv, and UALCAN database were used for evaluating the genomic mechanism. Moreover, the Tumor Immune Estimation Resource dataset and QUANTISEQ algorithm revealed that DDX1 expression positively correlates with immune infiltrating cells. We also identified the DDX1-related differentially expressed genes (DEGs) and explored their biological functions by GO, KEGG, and GSEA analyses, which indicated that DDX1 may regulate the progression of HCC. In general, increased DDX1 expression predicts a poor prognosis and drives the progression of HCC.

Cryptotanshinone inhibits prostaglandin E2 production and COX-2 expression via suppression of TLR4/NF-κB signaling pathway in LPS-stimulated Caco-2 cells.

Crytotanshinone (CTN), one of the main constituents of Salvia miltiorrhiza, has been known to exhibit antioxdative, anti-inflammatory and other important therapeutic activities. The aim of this study was to evaluate the effect of CTN on prostaglandin E2 and COX-2 production in LPS-stimulated human intestinal cells (Caco-2 cells). Caco-2 cells were stimulated with LPS in the presence or absence of CTN. The production of prostaglandin E2 (PGE2) was detected by ELISA. The expression of COX-2 was detected by qRT-PCR and Western blot. The extent of phosphorylation of IκB-α, NF-κB p65 and the expression of TLR4 were detected by western blot. The results showed that CTN dose-dependently inhibited the expression of COX-2 both in mRNA and protein levels, resulting in a decreased production of PGE2. We also found that CTN suppressed LPS-induced NF-κB activation and IκBα degradation. Furthermore, CTN inhibited the expression of TLR4 up-regulated by LPS. These results suggest that CTN exerts an anti-inflammatory property by inhibiting TLR4/NF-κB signaling pathway and the release of pro-inflammatory mediators. These findings suggest that CTN may be a therapeutic agent against intestinal inflammatory diseases.

Retraction Notice to: lncRNA SPRY4-IT1 Regulates Cell Proliferation and Migration by Sponging miR-101-3p and Regulating AMPK Expression in Gastric Cancer.

[This retracts the article DOI: 10.1016/j.omtn.2019.04.030.].

[Correlations of genetic polymorphisms of tumor necrosis factor-related apoptosis-inducing ligand gene and its plasma phenotype with ulcerative colitis].

OBJECTIVE: To explore the correlations of genetic polymorphisms in tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) gene and the plasma levels of soluble TRAIL (sTRAIL) with ulcerative colitis (UC). METHODS: From May 2004 to April 2011, a total of 393 UC patients were recruited from Second and First Affiliated Hospitals of Wenzhou Medical College and Second Renmin Hospital of Wenzhou City. During the same period, a total of 1292 healthy controls were recruited from Physical Examination Center at Second Affiliated Hospital of Wenzhou Medical College. After PCR amplification, the genetic polymorphisms in TRAIL (G1525A, G1588A, C1595T) genes were examined by direct sequencing, and the haplotype analysis were also performed in all study subjects. Furthermore, the plasma levels of sTRAIL were determined by enzyme-linked immunosorbent assay (ELISA). RESULTS: The frequencies of variant genotypes in TRAIL (G1525A, G1588A, C1595T) genes were significantly lower in the UC patients than those in the controls (all P < 0.01). Both of variant allele frequencies in TRAIL G1525A and G1588A were significantly decreased in UC patients (40.08% (315/786) vs 54.95% (1420/2584), 49.49% (389/786) vs 55.53% (1435/2584), both P < 0.01). However, the variant allele frequency in TRAIL C1595T gene was not significantly lower in the UC patients (P = 0.133). According to disease severity, the UC patients were divided into mild, intermediate and severe groups. The frequencies of variant allele (T) and genotype (CT + TT) in TRAIL C1595T gene were also significantly higher in the patients with severe UC than those in others (63.50% (127/200) vs 49.15% (288/586), 77.00% (77/100) vs 61.43% (180/293), both P < 0.01). In haplotype analysis, the frequency of GAT haplotype was significantly higher in the UC patients than that in the controls. However, the frequency of AAT haplotype was significantly lower in the UC patients (both P < 0.01). Furthermore, the plasma levels of sTRAIL were significantly higher in the UC patients than those in the controls ((1.05 ± 0.48) vs (0.96 ± 0.90) ng/L, P < 0.01). CONCLUSION: The genetic polymorphisms of TRAIL (G1525A, G1588A, C1595T) and the plasma levels of sTRAIL are correlated with UC in Chinese patients.

LINC00665:A Promising Biomarker in Gastrointestinal Tumors.

An increasing volume of studies has reported that long non-codingRNAs (lncRNAs) are involved in the carcinogenesis of many different cancers. Especially in gastrointestinal tumors, lncRNAs are found to participate in various physiological and pathological processes. LncRNAs can regulate gene expression at multiple levels, including transcriptional, post-transcription, translational, and post-translational levels. Long intergenic non-protein coding RNA 665(LINC00665), a novel cancer-related lncRNA, is frequently dysregulated in multiple gastrointestinal tumors, including gastric and colorectal cancers, hepatocellular carcinoma, and so on. In this review, we analyzed the expression and prognostic value of LINC00665 in human gastrointestinal tumors, systematically summarized the current literature about the clinical significance of this lncRNA, and explored the regulatory mechanisms of LINC00665 as a competing endogenous RNA (ceRNA) in tumor progression. Consequently, we concluded that LINC00665 might act as a prognostic biomarker and a potential target for gastrointestinal tumor diagnosis and treatment.

Influence of Vitamin D3 Supplementation on Infliximab Effectiveness in Chinese Patients With Crohn's Disease: A Retrospective Cohort Study.

Background: It remains uncertain whether vitamin D3 (vitD3) supplementation is beneficial for remission of Crohn's disease (CD). The influence of vitD3 supplementation on Infliximab (IFX) effectiveness was analyzed in Chinese CD patients. Methods: In this retrospective cohort study, moderate-to-severe CD patients, who were bio-naïve and prescribed with IFX treatment for at least 54 weeks, were recorded from January 2014 to December 2019. VitD3 supplementation was defined as patients additionally took oral vitD3 (125 IU/d) within 3 days after the first infusion and persisted in the whole follow-up period. Disease activity was assessed using Harvey-Bradshaw Index (HBI). Serum cytokine profiles (IL-2, IL-4, IL-6, IL-10, TNF-α, and IFN-γ) were quantitatively analyzed in a subset of all patients at baseline and 54-week after intervention. Results: Among 73 enrolled patients, 37 took vitD3 regularly (D3-patients), the others (non-D3-patients) did not. At 54-week, the mean 25-hydroxyvitaminD level increased in D3-patients (20.33 vs. 15.07 ng/mL, P < 0.001). The clinical remission rate was higher in D3-patients compared to non-D3-patients (83.8 vs. 61.6%, P = 0.030). The decrease of HBI from baseline to 54-week was more in D3-patients than non-D3-patients (7.41 ± 3.0 vs. 6.28 ± 2.75, P = 0.023). Furthermore, vitD3 supplementation was independently related to the increase of remission rate at 54-week in D3-patients (ß = -1.667, P = 0.015). The benefit of vitD3 supplementation was significant only in patients with deficient vitD3 (all P < 0.05), but not in non-deficient vitD3. A total of nine patients (four non-D3-patients and five D3-patients) were selected to determine serum cytokine profiles after 54-week IFX treatment. In non-D3-patients, the decreases of TNF-α and IL-6 at 54-week were more obvious than at baseline (P = 0.032, 0.022, respectively). In D3-patients, however, only IL-10 increased at 54-week compared with its baseline value (P = 0.037). Conclusions: VitD3 supplementation could improve IFX effectiveness in CD patients, especially for patients with vitD3 deficiency. This beneficial effect of vitD3 supplementation probably arose from the up-regulation of IL-10. Trial Registration: NCT04606017.

[The relationship of methylenetetrahydrofolate reductase G1793A gene polymorphism, hyperhomocysteinaemia and ulcerative colitis].

OBJECTIVES: The present study aimed to investigate the associations between genetic polymorphism of methylenetetrahydrofolate reductase (MTHFR) G1793A, plasma homocysteine (Hcy) levels, vitamin status and ulcerative colitis (UC) in a cohort of patients in Hubei Han nationality. METHODS: Two hundred and ninety-nine UC patients and 764 age- and sex-matched healthy controls were recruited in this study. Polymorphism of MTHFR G1793A was examined using a PCR-RELP method. Plasma levels of Hcy, folate and vitamin B12 were determined by enzymatic cycling assay and corpuscle immune chemiluminescence assay, respectively. RESULTS: Both variant allele and genotype frequencies in MTHFR G1793A gene were significantly higher in the UC patients compared to the controls (22.24% vs 14.20%, P < 0.001; 42.81% vs 26.97%, P<0.001, respectively). Plasma Hcy levels were increased in UC patients compared to the controls [(20.67 ± 6.42) mmol/L vs (13.21±5.11) mmol/L, P<0.001] while folate and vitamin B12 concentrations were significantly decreased [(11.37±6.34) nmol/L vs (14.89±7.21) nmol/L, P<0.001; (324.15±127.53) pmol/L vs (421.54±128.45) pmol/L, P<0.001, respectively]. Furthermore, hyperhomocysteinaemia (HHcy) and folate deficiency were also more prevalent in the UC patients (32.44% vs 25.78%, P=0.029; 23.41% vs 17.01%, P=0.016, respectively). CONCLUSIONS: Genetic polymorphism of MTHFR G1793A was strongly associated with UC. HHcy, folate deficiency and low vitamin B12 concentration were common phenomena in the UC patients of Hubei Han nationality. Our findings demonstrate that the genes related to Hcy metabolism may play an important role in the pathogenesis of UC.

lncRNA SPRY4-IT1 Regulates Cell Proliferation and Migration by Sponging miR-101-3p and Regulating AMPK Expression in Gastric Cancer.

Increasing evidence indicates that long noncoding RNA SPRY4 intronic transcript 1 (lncRNA SPRY4-IT1) has been reported to be associated with the progression of several cancers, but its expression level and the function of SPRY4-IT1 in the progression of gastric cancer (GC) have been rarely reported. Here we found that SPRY4-IT1 was upregulated in GC. In vitro experiments revealed that SPRY4-IT1 knockdown significantly inhibited GC cell proliferation by causing G1 arrest and promoting apoptosis, whereas SPRY4-IT1 overexpression promoted cell growth. Further functional assays indicated that SPRY4-IT1 overexpression significantly promoted cell migration and invasion. Bioinformatics analysis predicted that there is a SPRY4-IT1/miR-101-3p/AMPK axis in GC progression. A dual-luciferase reporter system validated the direct interaction of SPRY4-IT1, miR-101-3p, and AMPK. Western blot verified that the inhibition of SPRY4-IT1 decreased AMPK expression. Furthermore, silencing SPRY4-IT1 suppressed GC growth in vivo. Importantly, we demonstrated that SPRY4-IT1 was upregulated in serum exosomes from GC patients and correlated with cancer metastasis. Altogether, silencing SPRY4-IT1 suppresses the progression of GC by interacting with miR-101-3p and decreasing inhibiting AMPK expression. Taken together, our study demonstrates that SPRY4-IT1 could act as a potential therapeutic target for GC patients.

MicroRNA-761 promotes the sensitivity of colorectal cancer cells to 5-Fluorouracil through targeting FOXM1.

Resistance to chemotherapy is a big challenge for treatment of patients with colorectal cancer; however; the mechanism underlying chemoresistance in colorectal cancer cell has not been elucidated. MicroRNAs (miRNAs) are new players in the development of drug chemoresistance. In our study, we indicated that overexpression of miR-761 promoted the sensitivity of colorectal cancer cells to 5-Fluorouracil (5-FU). miR-761 expression was downregulated in colorectal cancer cell lines and tissues. miR-761 expression was lower in patients with low grade than in patients with high grade. In additon, we showed that elevated expression of miR-761 suppressed colorectal cancer cell proliferation, cell cycle, colony formation and cell invasion. We identified that FOXM1 was a direct target gene of miR-761 in colorectal cancer cell. FOXM1 expression was upregulated in colorectal cancer tissues compare to the adjacent non-tumor tissues. MiR-761 expression was negatively associated with the expression of FOXM1 in colorectal cancer tissues. Elevated expression of FOXM1 suppressed the sensitivity of miR-761-overexpressing HT29 cells to 5-FU. We also indicated that FOXM1 overexpression promoted cell proliferation, cycle and invasion of miR-761-overexpressing HT29 cells. These data suggested that miR-761 played a tumor suppressor miRNA in colorectal cancer progression and reduced miR-761 expression might be a major mechanism for 5-FU resistance in colorectal cancer cell.

High-Performance All-Solution-Processed Flexible Photodetector Arrays Based on Ultrashort Channel Amorphous Oxide Semiconductor Transistors.

Amorphous oxide semiconductor (AOS) field-effect phototransistors (FEPTs) are promising candidates for emerging photodetectors. Unfortunately, traditional lateral AOS FEPTs suffer from low photosensitivity, slow response time and inadequate mechanical flexibility, which restrict their widespread commercial application. In this work, novel AOS-based vertical field-effect phototransistor (VFEPT) arrays are presented, where the semiconducting layer and source and drain electrodes are deposited by inkjet printing. Benefitted from the unique vertical structure and ultrashort channel length, the exciton dissociation, carrier transfer, and collection efficiency were dramatically enhanced, resulting in excellent photoelectric performance in VFEPT devices, which was better than that of the traditional lateral AOS phototransistors. Moreover, flexible AOS VFEPT arrays were investigated for the first time on polyimide substrates. Due to the unique vertical architecture, the carrier transport was negligibly affected by the strain-induced in-plane cracks of the semiconductor channel layer during the mechanical bending process, which overcame the maximum bending limit of traditional lateral AOS thin-film transistors to ensure a transistor technique that gives notable mechanical robustness against repeated mechanical bending. Hence, this work provided a new pathway in emerging applications for AOS photodetectors with sensitivity, transparency, and flexibility.

[The features and treatment of Xixia "May 17th" explosion accident].

OBJECTIVE: To retrospectively analyze the injury characteristics of victims and treatment strategies in the explosion accident on the 17th May 2018 in Xixia county (Xixia "May 17th" explosion accident). METHODS: Completion the Level Three treatment on time, which was depended on the leading role played by the regional trauma centers was the main rescuing mode of the work in Xixia county, where the primary and secondary treatments were the key parts. The three-level treatment model includes: the local hospital acts as a level-one emergency medical institution, county hospitals function as secondary emergency medical institutions, and other higher medical institutions are the tertiary first aid medical institutions. The pre-hospital and in-hospital emergency procedures were initiated immediately after the large-scale explosive burn being identified, the key to the successfully rescue was to set up a comprehensive treatment team for burns and trauma. Rescue team should involve burn department and other related departments, including the departments of emergency, general surgery, orthopedic, thoracic surgery, neurosurgery, plastic surgery, intensive care unit, blood transfusion unit, anesthesiology, and interventional radiology, etc. All the thirteen burned patients were male, with inhalation injury, blast injury, hemopneumothorax, brain injury, bone fractures, and etc. Eight of them (61.54%) had multiple organ dysfunction syndrome (MODS). MODS mainly involved respiratory, circulatory, liver, gastrointestinal tract, kidney and coagulation function. With the multi-discipline treatment, the wound of 6 severely-burned patients started healing and can be discharged after keeping the patency of airway, applying resuscitation fluid and comprehensive treatments such as debridement and dressing change. Among 7 patients with extensive deep burns, one case with skull-based fracture, open craniocerebral, extensive intracranial hemorrhage and hemopneumothorax, died 9 hours later. Another case died within 24 hours after injury due to obvious exudation on the site of early incision and relaxation of wound. The escharotomy, micro-dermis and allograft skin transplantation were carried out for five cases with extensive deep burns from the 4th day after the recovery of shock. One week later, the second stage of microsphere skin transplantation was performed. But all died of sepsis or fungal infection. RESULTS: (1) A total of 113 elderly patients with sepsis were enrolled in the final analysis, including 67 patients in sepsis group and 46 patients in septic shock group. Thirty-two patients were enrolled as healthy controls and 31 elderly patients with CAP as elderly pneumonia group. The PCT, CRP, Lac, APACHE II and SOFA scores of the patients in the three groups were higher than those of the healthy control group, and they were gradually increased with the severity of infection. There was no significant difference in gender or age among the groups. Compared with the healthy control group, the other three groups had higher LL-37 level after admission, the LL-37 levels in the sepsis group and the septic shock group were decreased with the prolongation of the hospitalization time, and they were lower than the pneumonia group at 7 days after admission [LL-37 (µg/L): 1 403.9±501.9, 1 517.1±676.4 vs. 1 608.4±816.2, both P > 0.05]. It was shown by correlation analysis that the LL-37 level in peripheral blood of elderly patients with sepsis was significantly negatively correlated with APACHE II score (r = -0.329, P = 0.007) and SOFA score (r = -0.344, P = 0.005), but no significant correlation with Lac was found (r = -0.128, P = 0.311). (2) The 28-day survival analysis revealed that of the 113 elderly patients with sepsis, 54 (47.8%) survived at 28 days and 59 (52.2%) died. There was no significant difference in gender, age, PCT or CRP levels at 1 day after admission between the two groups. The 1-day Lac, APACHE II and SOFA scores of the patients in the non-survival group were significantly higher than those in the survival group, they were gradually increased with the prolongation of the hospitalization time, and they were significantly higher than those in the survival group at 7 days after admission [Lac (mmol/L): 2.4 (1.4, 4.4) vs. 1.0 (0.8, 1.7), APACHE II score: 21.77±5.85 vs. 13.74±4.99, SOFA score: 9.62±4.78 vs. 3.18±2.71, all P < 0.01]. With the prolongation of admission, there was no significant change in LL-37 level of peripheral blood in the survival group. The LL-37 level in the non-survival group showed a downward tendency, and it was significantly lower than that in the survival group at 7 days after admission (µg/L: 1 277.8±642.6 vs. 1 620.6±461.6, P < 0.05). It was shown by ROC curve analysis that the LL-37 in peripheral blood, Lac, APACHE II score and SOFA score at 7-day of admission of elderly patients with sepsis had predictive value for prognosis, and LL-37 had the best predicted effect for 28-day death, the area under the ROC curve (AUC) of LL-37 was 0.670, 95% confidence interval (95%CI) = 0.513-0.757, when the optimal cut-off value was 1 283.0 µg/L, the sensitivity was 75.7%, and the specificity was 61.5%. CONCLUSIONS: MODS and infection often occur during the course especially for patients with extensive and deep burns due to the great explosion in Xixia county, most of whom were accompanied with MODS and infection. Therefore, assembling multi-discipline team for treating the group of explosively-burned patients can increase the survival rate and reduce the possibility of disability.

Impact of c-erbB-2 protein on 5-year survival rate of gastric cancer patients after surgery: a cohort study and meta-analysis.

OBJECTIVE: To explore the association of c-erbB-2 protein expression with clinicopathological characteristics and prognosis of gastric cancer (GC) after surgery. METHODS: A total of 133 patients undergoing surgical resection for GC between March 2006 and January 2009 in the Second Affiliated Hospital of Wenzhou Medical University were included in this study. c-erbB-2 protein expression was determined by immunohistochemistry. Afterwards, a meta-analysis was performed to further confirm the association between c-erbB-2 protein expression and GC by employing stringent inclusion and exclusion criteria. All data analyses were conducted with STATA 12.0 and SPSS 19.0. RESULTS: There was no significant difference in c-erbB-2 expression among patients with various parameters including age, gender and histological types (all p>0.05). Among 133 GC patients, 32 patients presented c-erbB-2-positive expression and 101 presented c-erbB-2-negative expression (24.1% vs. 75.9%). The c-erbB-2-positive expression rate was significantly higher in GC tissues of patients with lymph node metastasis than those without. Similarly, a significant increase in c-erbB-2 expression was observed in well/moderately differentiated GC tissues compared with poorly differentiated GC. Patients with negative c-erbB-2 expression had a higher 5-year survival rate than those with positive c-erbB-2 expression, which was consistent with the results of the meta-analysis (OR = 0.54, 95% CI 0.37-0.80, p = 0.002). CONCLUSIONS: Our study demonstrated that high expression of c-erbB-2 protein was strongly associated with lymph node metastasis, histological differentiation and 5-year survival rate in GC patients after surgery.

Dose-dependent effect of ghrelin on gastric emptying in rats and the related mechanism of action.

The aim of this study was to investigate the dose-dependent effect of ghrelin on gastric emptying in rats and the related mechanism of action. Sixty Wistar rats were randomized into control and test groups, which respectively received intraperitoneal injection of normal saline and ghrelin at different doses (0.5 nmol/kg, 1.0 nmol/kg, 1.5 nmol/kg, 2.0 nmol/kg, and 2.5 nmol/kg). After 45 minutes, all rats were gavaged with semisolid paste. The gastric emptying rate was determined 30 minutes later, and the plasma cholecystokinin level was tested by radioimmunoassay. The mean gastric emptying rate in the test groups was significantly higher than in the control group (38.24 ± 7.15% and 27.18 ± 2.37%, respectively, p < 0.05). Medium and high doses of ghrelin (1.0 nmol/kg, 1.5 nmol/kg, 2.0 nmol/kg, and 2.5 nmol/kg), but not low dose (0.5 nmol/kg), accelerated the gastric emptying. In addition, the plasma cholecystokinin level in the test groups was significantly higher than in the control group (p < 0.01). The gastric emptying rate was positively correlated with the plasma cholecystokinin level (p < 0.01). Intraperitoneal injection of ghrelin at medium and high doses significantly accelerated gastric emptying in rats.

Effects of psychological stress on small intestinal motility and expression of cholecystokinin and vasoactive intestinal polypeptide in plasma and small intestine in mice.

AIM: To investigate the effects of psychological stress on small intestinal motility and expression of cholecystokinin (CCK) and vasoactive intestinal polypeptide (VIP) in plasma and small intestine, and to explore the relationship between small intestinal motor disorders and gastrointestinal hormones under psychological stress. METHODS: Thirty-six mice were randomly divided into psychological stress group and control group. A mouse model with psychological stress was established by housing the mice with a hungry cat in separate layers of a two-layer cage. A semi-solid colored marker (carbon-ink) was used for monitoring small intestinal transit. CCK and VIP levels in plasma and small intestine in mice were measured by radioimmunoassay (RIA). RESULTS: Small intestinal transit was inhibited (52.18+/-19.15% vs 70.19+/-17.79%, P<0.01) in mice after psychological stress, compared to the controls. Small intestinal CCK levels in psychological stress mice were significantly lower than those in the control group (0.75+/-0.53 microg/g vs 1.98+/-1.17 microg/g, P<0.01), whereas plasma CCK concentrations were not different between the groups. VIP levels in small intestine were significantly higher in psychological stress mice than those in the control group (8.45+/-1.09 microg/g vs 7.03+/-2.36 microg/g, P<0.01), while there was no significant difference in plasma VIP levels between the two groups. CONCLUSION: Psychological stress inhibits the small intestinal transit, probably by down-regulating CCK and up-regulating VIP expression in small intestine.