[Bacterial Community and Diversity of River Ecosystems on the Qinghai-Tibet Plateau Based on 16S rRNA Gene Sequencing].

In recent years, the ecosystems on the Qinghai-Tibet Plateau (QTP) have been facing a high risk of degradation due to the impacts of climate change and human activities. As one of the important components in river ecosystems, microbial communities can reflect the overall changes in the watershed and are regarded as indicators of the health of river ecosystems. In order to investigate the diversity and composition characteristics of bacterial communities in river ecosystems on the QTP, 65 samples were collected from the Yellow River, Yangtze River, Lancang River, Nujiang River, Yarlung Tsangpo River, and Qaidam Basin on the QTP in July 2021 and were analyzed using 16S rRNA high-throughput sequencing. The results showed that the detected bacterial communities covered 65 phyla and 1311 genera in total. Bacterial communities had high α-diversity indexes across the rivers, indicating that the bacterial richness and diversity in rivers on the QTP were at a high level. Among them, Chao and observed OTUs had significantly negative relationships with SRP/TP. The dominant phyla were Proteobacteria, Bacteroidota, Actinobacteriota, and Cyanobacteria. The dominant classes were γ-proteobacteria, Bacteroidia, and α-proteobacteria. The dominant genera were Flavobacterium and Limnohabitans. The results of principal coordinate analysis and permutational MANOVA suggested significant differences in bacterial community structure among the rivers on the QTP. Canonical correspondence analysis showed that the significant environmental variables associated with the variation in the bacterial communities were physicochemical properties of the river water, including conductivity, pH, dissolved silicon, and dissolved organic carbon, as well as watershed characteristics, including the average normalized differential vegetation index, average slope, cumulative water channel distance, catchment size, proportion of shrub area, and average elevation. Among them, conductivity had the strongest influence on bacteria distribution on the QTP. These results provide a database and information for understanding the composition characteristics of microbial communities on the QTP and identifying environmental factors influencing the diversity of bacteria communities.

Food Patterns are Associated with Likelihood of CKD in US Adults.

We investigated the association between dietary patterns and prevalent chronic kidney diseases (CKD), in participants of the 2005-2012 US National Health and Nutrition Examination Survey (NHANES) conducted between 2005 and 2012, who had measured data on dietary intake and kidney function. Analyse of covariance (ANCOVA) and logistic regression models were employed to account for the survey design and sample weights. A total of 21,649 eligible participants (634 with and 20,015 without prevalent CKD) were included in the final analysis. Three food patterns together explained 50.8% of the variance of the dietary nutrients consumption. The first food pattern was representative of a diet containing high levels of saturated and mono-unsaturated fatty acids; the second food pattern comprised vitamins and trace elements; and the third food pattern was mainly representative of polyunsaturated fatty acids. The odd of prevalent CKD decreased across increasing quarters of vitamins and trace elements, so that the top quarter was associated with a 53% (95%CI: 42-62%) lower odds of CKD in age, sex and race adjusted logistic regression models. These results suggest that vitamins and trace elements intake are associated with lower risk of prevalent CKD.

Lipid accumulation product and visceral adiposity index are associated with dietary patterns in adult Americans.

In the present study, we aimed to examine the association between lipid accumulation product (LAP) and visceral adiposity index (VAI) with dietary pattern (DP) in the US adults. Participants of the National Health and Nutrition Examination Survey (NHANES) with data available on dietary intake from 2005 to 2010 were included. DPs were derived by principal component analysis. We applied analysis of covariance and multivariable-adjusted linear regressions accounting for the masked variance and utilizing the proposed weighting methodology. The analytical sample comprised 18,318 participants (mean age = 45.8 years), of whom 48.3% (n = 8607) were men with no age difference by gender (P = .126). The first DP was representative of a diet rich in carbohydrate and sugar, total fat and saturated fatty acid (SFA), high-caloric dieatry pattern; the second DP was highly loaded with vitamins, minerals and fiber (nutrient-dense dietary patten), and the third DP was mainly representative of high dietary polyunsaturated fatty acids (PUFAs) and monounsaturated fatty acids (MUFAs) (healthy fat DP). The adjusted (age, sex, race, physical activity, smoking, C-reactive protein) mean of LAP, VAI and glucose homeostasis indices increased across increasing quarters of the first DP score (all P < .001), while across increasing score of the second DP, the adjusted mean of LAP, VAI, glucose homeostasis indices decreased (all P < .001). Findings were similar in adjusted linear regressions models. Our findings support that affordable measurements, such as VAI and LAP, could be good alternative surrogate markers of visceral fat. They are also significantly related to DPs in same line as with glucose/insulin homeostasis and anthropometric indices.

Inflammatory Markers Are Positively Associated with Serum trans-Fatty Acids in an Adult American Population.

BACKGROUND AND AIM: The relationship between serum trans-fatty acids (TFAs) and systemic inflammation markers is unclear. We investigated the association of serum TFAs with high sensitivity C-reactive protein (hs-CRP) and fibrinogen in adult Americans. METHODS: The 1999 to 2000 National Health and Nutrition Examination Survey (NHANES) participants with measured data on hs-CRP and fibrinogen were included. TFAs were measured via capillary gas chromatography and mass spectrometry using negative chemical ionization. Analysis of covariance and multivariable-adjusted linear regression models were used to investigate the associations between these parameters, accounting for the survey design. RESULTS: Of the 5446 eligible participants, 46.8% (n = 2550) were men. The mean age was 47.1 years overall: 47.8 years in men and 46.5 years in women (p = 0.085). After adjustment for age and sex, mean serum TFAs rose with the increasing quarters of hs-CRP and fibrinogen (both p < 0.001). In linear regression models adjusted for age, sex, race, education, marital status, body mass index, and smoking, serum TFAs were an independent predictor of plasma hs-CRP and fibrinogen levels. CONCLUSION: A high level of TFAs appears to be a contributor to an unfavourable inflammatory profile. Because serum TFAs concentrations are affected by dietary TFA intake, these data suggest a possible contribution of TFAs intake modulation in the prevention of inflammation-related chronic diseases.

Changes in adiposity and other cardiometabolic risk factors following Roux-en-Y gastric bypass: A 12-month prospective cohort study in Chinese patients.

AIM: We aimed to investigate the changes in adiposity and other cardiometabolic risk factors in the year following Roux-en-Y gastric bypass (RYGB) in patients of Chinese ethnicity. METHODS: The study recruited 209 patients who met the indications for bariatric surgery. Adiposity and cardiometabolic risk factors were assessed at baseline and over the 12 months following surgery in all participants. SPSS® software was used for statistical analysis. RESULTS: The mean body mass index (BMI) was 29.98 kg/m2 at baseline and steadily decreased to 25.32 kg/m2 at 12 months, giving a relative change of -15.5% (p < 0.001). All of the lipid profile fractions except high-density lipoprotein (HDL) declined during the first 12 months of follow up; serum HDL increased during this time (all ANOVA p < 0.001). The mean fasting plasma glucose was 9.49 mmol/L at baseline and gradually decreased to 5.69 mmol/L at 12 months, giving a relative change of -40.0% (p < 0.001). CONCLUSION: Following the RYGB procedure, changes in measures of adiposity were paralleled by a significant improvement in cardiometabolic factors for 12 months after surgery.

The relationship of plasma Trans fatty acids with dietary inflammatory index among US adults.

BACKGROUND: It has been suggested that trans fatty acids (TFAs) play an important role in cardiovascular diseases. We investigated the association between plasma TFAs and the dietary inflammatory index (DII) ™ in US adults. METHODS: National Health and Nutrition Examination Survey (NHANES) participants with data on plasma TFAs measured from 1999 to 2010 were included. Energy-adjusted-DII ™ (E-DII ™) expressed per 1000 kcal was calculated from 24-h dietary recalls. All statistical analyses accounted for the survey design and sample weights. RESULTS: Of the 5446 eligible participants, 46.8% (n = 2550) were men. The mean age of the population was 47.1 years overall, 47.8 years for men and 46.5 years for women (p = 0.09). After adjustment for C-reactive protein, body-mass-index, smoking, race, age, education, and marital status in linear regressions, trans 9-hexadecenoic acid [ß coefficient 0.068 (95% CI: 0.032 to 0.188)], trans 11-octadecenoic acid [ß coefficient 0.143 (95% CI: 0.155 to 0.310)], trans 9-octadecenoic acid [ß coefficient 0.122 (95% CI: 0.120 to 0.277)], trans 9, and trans 12-octadienoic acid [ß coefficient 0.103 (95% CI: 0.090 to 0.247)] were positively associated with the DII (all p < 0.001). CONCLUSION: The association of plasma TFAs with a marker of dietary inflammation suggests an underlying mechanism in the initiation and progression of cardiovascular diseases.

Effect of Sodium-Glucose Cotransport-2 Inhibitors on Blood Pressure in People With Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analysis of 43 Randomized Control Trials With 22 528 Patients.

BACKGROUND: The sodium-glucose cotransporter 2 (SGLT2) inhibitors are a class of oral hypoglycemic agents. We undertake a systematic review and meta-analysis of prospective studies to determine the effect of SGLT2 on blood pressure (BP) among individuals with type 2 diabetes mellitus. METHODS AND RESULTS: PubMed-Medline, Web of Science, Cochrane Database, and Google Scholar databases were searched to identify trial registries evaluating the impact of SGLT2 on BP. Random-effects models meta-analysis was used for quantitative data synthesis. The meta-analysis indicated a significant reduction in systolic BP following treatment with SGLT2 (weighted mean difference -2.46 mm Hg [95% CI -2.86 to -2.06]). The weighted mean differences for the effect on diastolic BP was -1.46 mm Hg (95% CI -1.82 to -1.09). In these subjects the weighted mean difference effects on serum triglycerides and total cholesterol were -2.08 mg/dL (95% CI -2.51 to -1.64) and 0.77 mg/dL (95% CI 0.33-1.21), respectively. The weighted mean differences for the effect of SGLT2 on body weight was -1.88 kg (95% CI -2.11 to -1.66) across all studies. These findings were robust in sensitivity analyses. CONCLUSIONS: Treatment with SGLT2 glucose cotransporter inhibitors therefore has beneficial off-target effects on BP in patients with type 2 diabetes mellitus and may also be of value in improving other cardiometabolic parameters including lipid profile and body weight in addition to their expected effects on glycemic control. However, our findings should be interpreted with consideration for the moderate statistical heterogeneity across the included studies.

Effects of Roux-en-Y gastric bypass on insulin secretion and sensitivity, glucose homeostasis, and diabetic control: A prospective cohort study in Chinese patients.

BACKGROUND: To report on the effects of Roux-en-Y gastric bypass operation for obesity on measures of adiposity, insulin secretion and sensitivity, glucose homeostasis, and improvement in diabetic control in Chinese patients. METHODS: This was a prospective cohort study of 152 participants (81% with diabetes) who were recruited for bariatric operation. RESULTS: Mean body mass index was decreased by 18.1% from 30.31 ± 5.38 kg/m2 at baseline to 24.45 ± 3.79 kg/m2 at 2 years (P < .001). Indices of insulin secretion, including serum c-peptide (both fasted and at various time points during an oral glucose tolerance test) improved at the 3-year follow-up, with a significant improvement in insulin sensitivity and glucose homeostasis. CONCLUSION: The effects of Roux-en-Y gastric bypass 3 years postoperative on adiposity were paralleled by a significant improvement in insulin secretion and sensitivity, and glucose tolerance.

Impact of the dietary fatty acid intake on C-reactive protein levels in US adults.

Growing evidence suggests that the effects of diet on cardiovascular disease (CVD) occur through mechanisms involving subclinical inflammation. We assessed whether reported dietary fatty acid intake correlates with a serum high-sensitivity C-reactive protein (hs-CRP) concentration in a population-based sample of US men and women.In this cross-sectional analysis, participants were selected from the US National Health and Nutrition Examination Survey (NHANES) and restricted to those with available data on dietary intake, biochemical and anthropometric measurements from 2001 to 2010. All statistical analyses accounted for the survey design and sample weights by using SPSS Complex Samples v22.0 (IBM Corp, Armonk, NY).Of the 17,689 participants analyzed, 8607 (48.3%) were men. The mean age was 45.8 years in the overall sample, 44.9 years in men, and 46.5 years in women (P = 0.047). The age-, race-, and sex-adjusted mean dietary intakes of total polyunsaturated fatty acids (PUFAs), PUFAs 18:2 (octadecadienoic), and PUFAs 18:3 (octadecatrienoic) monotonically decreased across hs-CRP quartiles (P < 0.001), whereas dietary cholesterol increased across hs-CRP quartiles (P < 0.001)This study provides further evidence of an association between fatty acid intake and subclinical inflammation markers. hs-CRP concentrations are likely modulated by dietary fatty acid intake. However, the causality of this association needs to be demonstrated in clinical trials.

Impact of different types of tree nut, peanut, and soy nut consumption on serum C-reactive protein (CRP): A systematic review and meta-analysis of randomized controlled clinical trials.

BACKGROUND: The effects of different types of tree nut, peanut, and soy nut consumption on serum C - reactive protein (CRP) are not well established. we aimed to undertake a systematic review and meta-analysis of prospective studies to determine the effect of nut consumption (tree nuts, peanuts, and soy nuts) on serum CRP. METHOD: PubMed-Medline, Web of Science, Cochrane Database, and Google Scholar databases were searched (up until April 20 2016) to identify prospective studies evaluating the impact of tree nut, peanut, and soy nut consumption on serum CRP. Random effects models meta-analysis was used for quantitative data synthesis. Sensitivity analysis was conducted using the leave-one-out method. Heterogeneity was quantitatively assessed using the I index. Systematic review registration: CRD42016038044. RESULTS: From a total of 844 entries identified via searches, 20 studies were included in the final selection. The meta-analysis indicated a nonsignificant increase in serum CRP concentrations following nut consumption (weighted mean difference [WMD] 0.17 mg/L, (95% CI -0.67 to 0.33, I 52.1%). The WMDs for IL6 was -0.06(ng/dL), (95% CI -0.69 to 0.56, I 9.6%), -0.71(mg/dL), (95% CI -1.11 to -0.30, I 6.3%), for leptin, and -0.60(mg/dL), (95% CI -1.88 to 0.68, I 5.6%) for adiponectin, and -0.18(mg/dL), (95% CI -1.24 to 0.88, I 9.3%) for IL10 and -0.37 (pg/mL), (95% CI -0.90 to 0.16, I 7.9%) for TNF-α. These findings were robust in sensitivity analyses. CONCLUSIONS: This meta-analysis suggests that nut consumption significantly decrease leptin while have no significant effect on CRP, IL6, adiponectin, IL10, and TNF-α.

The effect of ginger supplementation on serum C-reactive protein, lipid profile and glycaemia: a systematic review and meta-analysis.

AIM: To undertake a systematic review and meta-analysis of prospective studies to determine the effect of ginger supplementation on serum C-reactive protein (CRP), lipid profile, and glycaemia. METHOD: PubMed-MEDLINE, Web of Science, Cochrane Database, and Google Scholar databases were searched (up until July 2016) to identify prospective studies evaluating the impact of ginger supplementation on serum CRP. Random-effects model meta-analysis was used for quantitative data synthesis. Sensitivity analysis was conducted using the leave-one-out method. Heterogeneity was quantitatively assessed using the I2 index. Systematic review registration: CRD42016035973. RESULTS: From a total of 265 entries identified via searches, 9 studies were included in the final selection. The meta-analysis indicated a significant reduction in serum CRP concentrations following ginger supplementation [weighted mean difference (WMD)-0.84 mg/L (95% CI -1.38 to -0.31, I2 56.3%)]. The WMD for fasting blood glucose and HbA1c was -1.35 mg/dl (95% CI -2.04 to -0.58, I2 12.1%) and -1.01 (95% CI -1.28 to -0.72, I2 9.4%), respectively. Moreover, high-density lipoprotein and triglyceride significantly improved after ginger administration [1.16 mg/dl (95% CI 0.52 to 1.08, I2 12.3%) and -1.63 mg/dl (95% CI -3.10 to -0.17, I2 8.1%), respectively]. These findings were robust in sensitivity analyses. Random-effects meta-regression revealed that changes in serum CRP levels were independent of the dosage of ginger supplementation (slope -0.20; 95% CI -0.95 to 0.55; p=0.60). CONCLUSIONS: This meta-analysis suggests that ginger supplementation significantly reduces serum CRP and improves glycaemia indexes and lipid profile. Randomized control trials with larger sample size and with a longer-term follow-up period should be considered for future investigations.

[Establishment of a new gastric bypass animal-model with GK rats].

OBJECTIVE: To establish a new gastric bypass animal-model with Goto-Kakizaki rats whose different parts of the small intestine were bypassed while stomach was not bypassed. METHODS: Forty male 3-month-old GK rats were randomly divided into 4 groups: group I (sham operation), group II (duodenum bypassed), group III (jejunum bypassed), group IV (ileum bypassed). Fasting plasma glucose was measured before operation and the 1st, 4th,and 8th week after operation in all the rats, the body weight of all the rats were measured simultaneously. RESULTS: The survival rate of operation for the rats was 95%. Two rats in group IV (died on the first day after operation. The mean fasting plasma glucose concentration of the rats in group II, III, IV (declined obviously 4 weeks after gastric bypass [group II (12.02+/-1.97) vs (6.36+/-0.50) mmol/L, group III (13.42+/-1.66) vs (5.96+/-0.53) mmol/L, group IV (14.32+/-2.82) vs (5.18+/-0.49) mmol/L, all P <0.01], but there were no significant differences among the gastric bypassed groups. The weight of rats in group I, II, III (increased obviously after gastric bypass [group I (253.6+/-9.37) vs (367.0+/-23.70) g, group II (268.2+/-7.95) vs (384.8+/-16.12) g, group III (253.0+/-6.20) vs (323.0+/-16.40) g, all P <0.05] except the rats in group IV ([(262.0+/-13.47) vs(185.8+/-11.56) g]. CONCLUSIONS: The mean fasting plasma glucose concentration of the GK rats decreases obviously after gastric bypass through different parts of small intestine. The fasting plasma glucose concentration is not associated with the length of small intestine and body weight.

[Association between toll like receptor 4 (896A>G) mutations and pancreatic necrotic infection in severe acute pancreatitis].

OBJECTIVE: To determine the relationship between Toll like receptor (TLR) 4 (896A>G) mutations and pancreatic necrotic infection in acute pancreatitis (AP). METHODS: TLR4 (896A>G) mutations were detected by mispairing PCR-RFLP analysis technique in the patients with pancreatic necrosis and healthy volunteers. RESULTS: (1) All of the TLR4 mutations were heterozygotes; (2) The G allele frequencies of TLR4 genes were significantly higher in the patients with pancreatic infection than in the healthy volunteers; (3) The incidence of gram-negative infection was significantly higher in the patients with the TLR4 mutations [15 (44.1%) of 34] than that in the wild type population [15(18.5%) of 81]. CONCLUSION: TLR4 (896A>G) mutations are associated with the infection of pancreatic necrosis in the patients with AP.

Toll-like receptor 4 Asp299Gly polymorphism is associated with an increased risk of pancreatic necrotic infection in acute pancreatitis: a study in the Chinese population.

OBJECTIVES: To detect the frequency of Toll-like receptor (TLR) 4896A>G (Asp299Gly) polymorphism in acute pancreatitis (AP) patients and to determine the relationship between polymorphism and pancreatic necrotic infection. METHODS: The allele frequency of TLR4 Asp299Gly was surveyed by mispairing polymerase chain reaction-restriction fragment length polymorphism analysis technique in AP patients with pancreatic necrosis and healthy volunteers, respectively. RESULTS: All individuals with TLR4 Asp299Gly polymorphism were heterozygotes. Compared with healthy volunteers (5.6%), TLR4 896G allele frequencies was significantly higher in AP patients with pancreatic infection (20%), the incidence of gram-negative infection was significantly higher in AP patients with TLR4 Asp299Gly polymorphism (15 [44%]/34) than that in AP patients without TLR4 polymorphism (15 [18%]/81). CONCLUSIONS: Toll-like receptor 4 Asp299Gly polymorphism is associated with the infection of pancreatic necrosis in AP. Patients who carried TLR4 896A>G mutation is susceptible to pancreatic gram-negative bacteria infection.

[Distribution of micrometastatic nodules of low rectal cancer in mesorectum: a pathological study using whole-mount sections].

OBJECTIVE: To investigate the regional spread of micrometastatic nodules in the mesorectum from low rectal cancer, and provide further pathological evidence to optimize radical resection procedure for rectal cancer. METHODS: A total of 62 patients with low rectal cancer underwent low anterior resection and total mesorectal excision (TME) was included in this study. Surgical specimens were sliced transversely and serial embedded blocks were made at 2.5 mm interval, and paraffin sections were stained with hematoxylin and eosin. The mesorectum on whole-mount sections was divided into three regions: outer region of mesorectum (ORM), middle region of mesorectum (MRM) and inner region of mesorectum (IRM). Microscopic spread were examined microscopically on the sections for the distribution in different mesorectal regions, frequency, types, involvement of lymphatic system and correlation with the primary tumor. RESULTS: Microscopic spread of the tumor in mesorectum and ORM was observed in 38.7% (24/62) and 25.8% (16/62) of the patients, respectively. Circumferential resection margin (CRM) involved by microscopic tumor foci occurred in 6.5% (4/62) of the patients, and distal mesorectum (DMR) involvement was recorded in 6.5% (4/62) with a spread extent within 3 cm of distal border of the main lesions. Most (20/24) of the patients with microscopic spread in mesorectum were in TNM stage III. CONCLUSION: Results of the present study support that complete excision of mesorectum without destruction of the ORM is essential for surgical management of low rectal cancer, and an optimal DMR clearance resection margin should not be less than 4 cm.

Microcirculatory detection of Toll-like receptor 4 in rat pancreas and intestine.

This paper was aimed to detect Toll-like receptor 4 (TLR4) microcirculatory expression and localization in rat pancreas and intestine. Acute pancreatitis (AP) was induced by twice injections of cerulein (20 mug in total) and acute necrotizing pancreatitis (ANP) was induced by intraductal injection of 5% taurocholate (1 ml/kg.bw). Reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry (IHC) were used to detect and localize TLR4 in the pancreas and intestine. Results showed that RT-PCR of RNA isolated from pancreatic and intestinal tissue yielded the predicted amplicon for TLR4; IHC analysis localized TLR4 expression to the endothelium of pancreatic arteriole, venule, acinar capillary network and sinusoidal capillary of endocrine islet; TLR4 expression in intestine was principally in the microvascular endothelium and leucocytes within the mucosa lamina propria. TLR4 staining in intestine was more intense in taurocholate-induced pancreatitis (TIP) than that in cerulein-induced pancreatitis (CIP). In conclusion, TLR4 could be detected in the pancreatic and intestinal microcirculation, suggesting TLR4 involved in the microcirculatory impairment in AP; the more intense intestinal TLR4 expression in TIP suggests a potential risk for secondary infection.

[Expression of phosphatase of regenerating liver-3 mRNA and its clinical implications in human colorectal carcinoma].

OBJECTIVE: To investigate the expression of phosphatase of regenerating liver-3 (PRL- 3) mRNA and evaluate its relationship with tumor invasion and metastasis in human colorectal carcinoma. METHODS: The expression level of PRL-3 mRNA was examined semi-quantitatively in surgically resected tumor specimens, paired paratumor normal tissues from 46 CRC patients, metastatic lymph nodes and liver metastases from 18 cases with metastasis,adenoma tissues from 6 patients with colorectal adenoma (CRA). In addition,the mutation of PRL-3 gene was examined by PCR-SSCP. RESULTS: The PRL-3 mRNA level was increased in primary CRC tissues as compared with paired paratumor normal tissues (1.6+/- 0.7 vs. 0.4+/- 0.1, P< 0.01), while no significant difference of its expression was found between CRA tissues and their adjacent normal mucosae (P> 0.05). However,the PRL-3 mRNA levels of liver metastases (2.1+/- 0.8) in 12 cases and metastatic lymph nodes (3.3+/- 1.0) in 6 cases were significantly higher compared with the matched primary lesions, normal tissues and negative-lymph nodes (P< 0.01). There was significant relation of the expression of PRL-3 mRNA with the clinicopathological features including Dukes stage, invasion depth and metastasis (P< 0.05), but no relation with sex,tumor size,degree of differentiation was found (P> 0.05). Abnormal electrolysis band was found in 1 of 6 cases with liver metastasis by PCR-SSCP analysis. CONCLUSION: PRL-3 gene plays an important role in tumor invasion and metastasis and may associated with carcinogenesis and development of CRC. There might exist some unknown mechanisms of overexpression and mutation of PRL-3 gene in CRC.

[Effects of analogs of pituitary adenylate cyclase activating polypeptide on acute pancreatitis in rats].

OBJECTIVE: To examine the effects of analogs of pituitary adenylate cyclase activating polypeptide (PACAP)--PACAP6-27 (10, 100 microg/kg) and (4-Cl-D-Phe6, Leu17)VIP (10, 100 microg/kg) on the pancreata of normal rats and on the development of experimental acute pancreatitis. METHODS: Male Wistar rats were allocated into normal control groups, experimental acute pancreatitis groups and PACAP analog intervention groups. Acute pancreatitis was induced with s.c. cerulein and intraductal sodium taurocholate; PACAP analogs were infused intravenously immediately after pancreatitis induction. Pancreatic morphology was observed at 4 h, and serum amylase, pancreatic water content and PACAP contents were measured. RESULTS: It was found that PACAP6-27 induced pancreatic edema, inflammatory cell infiltration, and elevation of serum amylase [(1464.33 +/- 265.6)-(1692.17 +/- 312.18)] IU/L vs (520.8 +/- 163.27) IU/L of control, P < 0.05); that PACAP6-27 aggravated vacuolization of pancreatic acinar cells in cerulein-induced pancreatitis with hemorrhage and fatty and parenchymal necrosis; and that the pathological changes of cerulein plus 100 microg/kg PACAP group were similar to those of sodium taurocholate-induced pancreatitis. Pancreatic hemorrhage, vacuolization of acinar cells and parenchymal necrosis in sodium taurocholate-induced pancreatitis were worsened by PACAP6-27. (4-Cl-D-Phe6, Leu17)VIP had similar effects. ELISA showed that pancreatic and duodenal levels of PACAP were increased in cerulein- and sodium taurocholate-induced pancreatitis. CONCLUSION: PACAP6-27 and (4-Cl-D-Phe6, Leu17)VIP could induce mild pancreatitis and aggravate experimental acute pancreatitis. PACAP probably plays a role in the pathogenesis of acute pancreatitis.

Pituitary adenylate cyclase activating-peptide and its receptor antagonists in development of acute pancreatitis in rats.

AIM: Pituitary adenylate cyclase activating-peptide (PACAP) is a late member of the secretin/glucagon/vasoactive intestinal peptide (VIP) family of brain-gut peptides. It is unknown whether PACAP takes part in the development of acute pancreatitis and whether PACAP or its antagonists can be used to suppress the progression of acute pancreatitis. We investigated the actions of PACAP and its receptor antagonists in acute pancreatitis on rats. METHODS: Acute pancreatitis was induced in rats with caerulein or 3.5% sodium taurocholate. The rats were continuously infused with 5-30 microg/kg PACAP via jugular vein within the first 90 min, while 10-100 microg/kg PACAP6-27 and (4-Cl-D-Phe6, Leu17) VIP (PACAP receptor antagonists) were intravenously infused for 1 h. Biochemical and histopathological assessments were made at 4 h after infusion. Pancreatic and duodenal PACAP concentrations were determined by enzyme-linked immunosorbent assay (ELISA). Chinese ink-perfused pancreas was fixed, sectioned and cleared for counting the functional capillary density. RESULTS: PACAP augmented caerulein-induced pancreatitis and failed to ameliorate sodium taurocholate-induced pancreatitis. ELISA revealed that relative concentrations of PACAP in pancreas and duodenum were significantly increased in both sodium taurocholate- and caerulein-induced pancreatitis compared with those in normal controls. Unexpectedly, PACAP6-27 and (4-Cl-D-Phe6, Leu17) VIP could induce mild acute pancreatitis and aggravate caerulein-induced pancreatitis with characteristic manifestations of acute hemorrhagic/necrotizing pancreatitis. Functional capillary density of pancreas was interpreted in the context of pancreatic edema, and calibrated functional capillary density (calibrated FCD), which combined measurement of functional capillary density with dry weight/wet weight ratio, was introduced. Hyperemia or congestion, rather than ischemia, characterized pancreatic microcirculatory changes in acute pancreatitis. CONCLUSION: PACAP may take part in the pathogenesis of acute pancreatitis in rats. The two PACAP receptor antagonsits might act as partial agonists. Calibrated functional capillary density can reflect pancreatic microcirculatory changes in acute pancreatitis.

Differences in platelet endothelial cell adhesion molecule-1 expression between peripheral circulation and pancreatic microcirculation in cerulein-induced acute edematous pancreatitis.

AIM: To investigate the changes of platelet endothelial cell adhesion molecule-1 (PECAM-1) expression on polymorphonuclear leukocytes (PMNs) in peripheral circulation and pancreatic microcirculation in cerulein-induced acute edematous pancreatitis (AEP). METHODS: Fifty Wistar rats were randomly divided into control group (n = 10) and AEP group (n = 40). A model of AEP was established by subcutaneous injection of cerulein 5.5 and 7.5 mug/kg at 0 and 1 h after the beginning of experiment respectively. PECAM-1 expression on PMNs from splenic vein and inferior vena cava was determined by RT-PCR at mRNA level and determined by flow cytometry at protein level. RESULTS: In experimental rats, an increased PECAM-1 mRNA expression was seen from 4 to 8 h of AEP in peripheral circulation (0.77+/-0.25%, 0.76+/-0.28%, 0.89+/-0.30%, 1.00+/-0.21%), while in pancreatic microcirculation, expression decreased from 2 h and reached the lowest level at 6 h of AEP (0.78+/-0.29%, 0.75+/-0.26%, 0.62+/-0.28%, 0.66+/-0.20%). There were significant differences at 8-h time point of AEP between peripheral circulation and pancreatic microcirculation (1.00+/-0.21% vs 0.66+/-0.20%, P<0.05). Meanwhile, the difference at protein level was also found. CONCLUSION: A reverse expression of PECAM-1 on PMNs was found between peripheral circulation and pancreatic microcirculation, suggesting that inhibition of PECAM-1 expression may improve the pathological change of AEP.