Effect of Qingyitang on activity of intracellular Ca~(2 )-Mg~(2 )-ATPase in rats with acute pancreatitis

AIM:To study the change of intracellular calcium-magnesiumATPase (Ca~(2 )-Mg~(2 )-ATPase) activity in pancreas,liver andkidney tissues of rats with acute pancreatitis (AP),and toinvestigate the effects of Qingyitang (QYT) (Decoction forclearing the pancreas) and tetrandrine (Tet) and vitamin E(VitE) on the activity of Ca~(2 )-Mg~(2 )-ATPase.METHODS:One hundred and five Sprague-Dawley ratswere randomly divided into:normal control group,AP group,treatment group with QYI (1 ml/100 g) or Tet (0.4 ml/100 g)or VitE (100 mg/kg).AP model was prepared by a retrogradeinjection of sodium taurocholate into the pancreatic duct.Tissues of pancreas,liver and kidney of the animals weretaken at 1 h,5 h,10 h respectively after AP induction,andthe activity of Ca~(2 )-Mg~(2 )-ATPase was studied using enzyme-histochemistry staining.Meanwhile,the expression of Ca~(2 )-Mg~(2 )-ATPase of the tissues was studied by RT-PCR.RESULTS:The results showed that the positive rate ofCa~(2 )-Mg~(2 )-ATPase in AP group (8.3%,25%,29.2%) waslower than that in normal control group (100%) in all tissues(P<0.01),the positive rate of Ca~(2 )-Mg~(2 )-ATPase in treatmentgroup with QYT (58.3%,83.3%,83.3%),Tet (50.0%,70.8%,75.0%) and VitE (54.2%,75.0%,79.2%) was higherthan that in AP group (8.3%,25.0%,29.2%) in all tissues(P<0.01).RT-PCR results demonstrated that in treatmentgroups Ca~(2 )-Mg~(2 )-ATPase gene expression in pancreastissue was higher than that in AP group at the observingtime points,and the expression at 5 h was higher than thatat 1 h.The expression of Ca~(2 )-Mg~(2 )-ATPase in liver tissuewas positive,but without significant difference betweendifferent groups.CONCLUSION:The activity and expression of intracellularCa~(2 )-Mg~(2 )-ATPase decreased in rats with AP,suggesting thatCa~(2 )-Mg~(2 )-ATPase may contribute to the occurrence anddevelopment of cellular calcium overload in AP.QYT,Tetand VitE can increase the activity and expression of Ca~(2 )-Mg~(2 )-ATPase and may relieve intracellular calcium overloadto protect the tissue and cells from injuries.     

Reversing gastric mucosal alterations during ethanol-induced chronic gastritis in rats by oral administration of Opuntia ficus-indica mucilage

AIM: To study the effect of mucilage obtained from cladodes of Opuntia ficus-indica (Cactaceae) on the healing of ethanol-induced gastritis in rats. METHODS: Chronic gastric mucosa injury was treated with mucilage (5 mg/kg per day) after it was induced by ethanol. Lipid composition, activity of 5'-nucleotidase (a membrane-associated ectoenzyme) and cytosolic activities of lactate and alcohol dehydrogenases in the plasma membrane of gastric mucosa were determined. Histological studies of gastric samples from the experimental groups were included. RESULTS: Ethanol elicited the histological profile of gastritis characterized by loss of the surface epithelium and infiltration of polymorphonuclear leukocytes. Phosphatidylcholine (PC) decreased and cholesterol content increased in plasma membranes of the gastric mucosa. In addition, cytosolic activity increased while the activity of alcohol dehydrogenases decreased. The administration of mucilage promptly corrected these enzymatic changes. In fact, mucilage readily accelerated restoration of the ethanol-induced histological alterations and the disturbances in plasma membranes of gastric mucosa, showing a univocal anti-inflammatory effect. The activity of 5'-nucleotidase correlated with the changes in lipid composition and the fluidity of gastric mucosal plasma membranes. CONCLUSION: The beneficial action of mucilage seems correlated with stabilization of plasma membranes of damaged gastric mucosa. Molecular interactions between mucilage monosaccharides and membrane phospholipids, mainly PC and phosphatidylethanolamine (PE), may be the relevant features responsible for changing activities of membrane-attached proteins during the healing process after chronic gastric mucosal damage.     

Hypoxia preconditioning protects Ca~(2+)-ATPase activation of intestinal mucosal cells against R/I injury in a rat liver transplantation model

AIM To investigate the effect of ischaemia and reperfusion(I/R) injury on the Ca~(2+)-ATPase activation in the intestinal tissue of a rat autologous orthotopic liver transplantation model and to determine if hypoxia preconditioning(HP) therapy induces HIF-1α to protect rat intestinal tissue against I/R injury.METHODS Rats received non-lethal hypoxic preconditioning therapy to induce HIF-1α expression. We used an autologous orthotopic liver transplantation model to imitate the I/R injury in intestinal tissue. Then, we detected the microstructure changes in small intestinal tissues, Ca~(2+)-ATPase activity, apoptosis, and inflammation within 48 h postoperatively. RESULTS HIF-1α expression was significantly increased in intestinal tissue at 12 h postoperatively in rats that were exposed to a hypoxic environment for 90 min compared with a non-HP group(HP vs AT, P = 0.0177). Pathological analysis was performed on the intestinal mucosa cells, and the cells in the HP group appeared healthier than the cells in the AT group. The Ca~(2+)-ATPase activity in the small intestinal cells in the AT group was significantly lower after the operation, and the Ca~(2+)-ATPase activity in the HP group recovered faster than that in the AT group at 6 h postoperatively(HP vs AT, P = 0.0106). BCL-2 expression in the HP group was significantly higher than that in the AT group at 12 h postoperatively(HP vs AT P = 0.0010). The expression of the inflammatory factors NO, SOD, IL-6, and TNF-α was significantly lower in the HP group than in the AT group.CONCLUSION Hypoxia-induced HIF-1α could protect intestinal mucosal cells against mitochondrial damage after I/R injury. HP could improve hypoxia tolerance in small intestinal mucosal cells and increase Ca~(2+)-ATPase activity to reduce the apoptosis of and pathological damage to intestinal cells. HP could be a useful way to promote the earlier recovery of intestinal function after graft procedure.     

Effect of emodin on mobility signal transduction system of gallbladder smooth muscle in Guinea pig with cholelithiasis

Objective: To study the effect of emodin on protein and gene expressions of the massagers in mobility signal transduction system of cholecyst smooth muscle cells in guinea pig with cholesterol calculus. Methods: The guinea pigs were randomly divided into 4 groups, such as control group, gall-stone(GS) group, emodin group and ursodesoxycholic acid(UA) group. Cholesterol calculus models were induced in guinea pigs of GS, emodin and UA groups of induced models by lithogenic diet, while emodin or UA were given to the corresponding group for 7 weeks. The histomorphological and ultrastructure change of gallbladder were detected by microscope and electron microscope, the content of plasma cholecystokinin(CCK) and [Ca~(2+)]i were analyzed successively by radioimmunoassay and flow cytometry. The protein and mR NA of Gsα, Giα and Cap in cholecyst cells were determined by western blotting and real time polymerase chain reaction(RT-PCR). Results: Emodin or UA can relieve pathogenic changes in epithelial cells and muscle cells in gallbladder of guinea pig with cholesterol calculus by microscope and transmission electron microscope. In the cholecyst cells of GS group, CCK levels in plasma and [Ca~(2+)]i decreased, the protein and m RNA of GS group were downregulated,the protein and m RNA of Gi and Cap were up-regulated. Emodin significantly decreased the formative rate of gallstone, improved the pathogenic change in epithelial cells and muscle cells, increased CCK levels in plasma and [Ca~(2+)]i in cholecyst cells, enhanced the protein and mR NA of Gs in cholecyst cells, reduced the protein and mR NA of Gi and Cap in cholecyst cells in guinea pig with cholesterol calculus. Conclusion: The dysfunction of gallbladder contraction gives rise to the disorders of mobility signal transduction system in cholecyst smooth muscle cells, including low content of plasma CCK and [Ca~(2+)]i in cholecyst cells, abnormal protein and mRNA of Gs, Gi and Cap. Emodin can enhance the contractibility of gallbladder and alleviate cholestasis by regulating plasma CCK levels, [Ca2+]i in cholecyst cells and the protein and mR NA of Gs, Gi and Cap.     

Peroxynitrite induced decrease in Na^＋, K^＋-ATPase activity is restored by taurine

AIM: Peroxynitrite (ONOO-) is a powerful oxidant shown to damage membranes. In the present study, the effect of taurine on changes of liver plasma membrane Na+, K+-ATPase induced by ONOO- was investigated. METHODS: Liver plasma membrane was exposed to ONOO-with or without taurine. Na+, K+-ATPase activity and lipid peroxidation as thiobarbituric acid reactive substances (TBARS) levels were measured. RESULTS: Different concentrations of ONOO- (100, 200, 500, and 1 000 μmol/L) were found to decrease liver plasma membrane Na+, K+-ATPase activity significantly. The depletion of enzyme activity was not concentration dependent. Effects of different concentrations of taurine on liver plasma membrane Na+, K+-ATPase activity were also measured. Taurine did not cause any increase in enzyme activity. When plasma membranes were treated with 200 μmol/L ONOO- with different concentrations of taurine, a restoring effect of taurine on enzyme activity was observed. TBARS levels were also measured and taurine was found to decrease the elevated values. CONCLUSION: Taurine is observed to act as an antioxidant of ONOO- to decrease lipid peroxidation and thus affect liver plasma membrane Na+, K+-ATPase by restoring its activity.     

Protective effect of selenium-enriched lactobacilluson CCI_4-induced liver injury in mice and its possible mechanisms

AIM: To study the protective effects and mechanisms of Se-enriched lactobacillus on liver injury caused by carbon tetrachloride(CCI_4) in mice. METHODS: Seventy-two ICR mice were randomly divided into four groups: normal group, CCl_4-induced model group, low Se-enriched lactobacillus treatment group(L-Se group), and high Se-enriched lactobacillus treatment group(H-Se group). During a 3-wk experimental period, the common complete diet was orally provided daily for normal group and model group, and the mice in L-Se and H-Se groups were given a diet with 2 and 4 mg of organoselenium from Se-enriched lactobacillus per kg feed, respectively. From the 2~(nd) wk of experiment, the model group, L-Se group, and H-Se group received abdominal cavity injection of olive oil solution containing 500 mL/L CCl_4(0.07 mL/100 g body mass) to induce liver injury, and the normal group was given olive oil on every other day for over 2 wk. In the first 2 wk post injection with CCl_4, mice in each group were killed. The specimens of blood, liver tissue, and macrophages in abdominal cavity fluid were taken. Then the activities of the following liver tissue injury-associated enzymes including glutathione peroxidase(GSH-Px), superoxide dismutase(SOD), alanine aminotransferase(ALT) and aspartate aminotransferase(AST) as well as malondialdehyde(MDA) content were assayed. Changes of phagocytic rate and phagocytic index in macrophages were observed with Wright-Giemsa stain. Plasma TNF-α level was measured by radioimmunoassay. The level of intracellular free Ca~(2+)([Ca~(2+)]_i) in hepatocytes was detected under a laser scanning confocal microscope. RESULTS: During the entire experimental period, the AST and ALT activities in liver were greatly enhanced by CCl_4 and completely blunted by both low and high doses of Se-enriched lactobacillus. The Se-enriched lactobacillusprotected liver homogenate GSH-Px and SOD activities were higher or significantly higher than those in model group and were close to those in normal group. CCl_4 significantly increased MDA content in liver homogenates, while administration of Se-enriched lactobacillus prevented MDA elevation. Phagocytic rate and phagocytic index of macrophages decreased after CCl_4 treatment compared to those in normal control, but they were dramatically rescued by Se-enriched lactobacillus, showing a greatly higher phagocytic function compared to model group. CCl_4 could significantly elevate plasma TNF-α and hepatocyte[Ca~(2+)]_i level, which were also obviously prevented by Se-enriched lactobacillus. CONCLUSION: Se-enriched lactobacillus can intervene in CCl_4-induced liver injury in mice by enhancing macrophage function activity to keep normal and beneficial effects, elevating antioxidant-enzyme activities and reducing lipid peroxidation reaction, inhibiting excessive release of TNF-α, preventing the dramatic elevation of [Ca~(2+)]_i in hepatocytes.     

Effects of long-term ethanol consumption on jejunal lipase and disaccharidase activities in male and female rats

AIM: To study the effect of long-term ethanol consumption on jejunal lipase and disaccharidase (sucrase, maltase, and lactase) activities in rats and its gender difference. METHODS: Age-matched male and female Wistar rats were fed control or ethanol-containing liquid diets for 12 wk following the Lieber-DeCarli model. According to both the plasma aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities, 40 rats were divided into four groups as follows: male control group (MC), male ethanol group (ME), female control group (FC), and female ethanol group (FE). RESULTS: After ethanol feeding for 12 wk, the results revealed that plasma AST and ALT activities of group ME were significantly increased by 58% and 92%, respectively, than those of group MC (P<0.05). Similarly, plasma AST and ALT activities of group FE were also significantly increased by 61% and 188%, respectively, than those of group FC (P<0.05). Fat accumulation was observed in both ethanol-treated groups, while fatty changes were more severe in group FE than those in group ME. The induction of hepatic microsomal cytochrome P450 2E1 (CYP2E1) was obviously seen in group ME and group FE, but was not detected in group MC and group FC. Jejunal lipase activity of group ME was significantly increased by 1.25-fold than that of group MC (P<0.05). In contrast to, sucrase, maltase, and lactase activities of group ME were significantly decreased by 63%, 62% and 67%, respectively, than those of group MC (P<0.05). Similarly, activities of these three enzymes of group FE were also significantly decreased by 43%, 46% and 52%, respectively, than those of group FC (P<0.05). There were no significant epithelial changes of the duodenal mucosa in any group. CONCLUSION: Long-term ethanol consumption significantly can increase jejunal lipase and decrease jejunal disaccharidase activities in both male and female rats.     

Immunohistochemical Study of the Expressions of TGFα and EGFR during Tolerant Cytoprotection of Gastric Mucosa under Stress

To study the influence of stress on gastric mucosal hydrophobicity and the content of phospholipid in gastric glandular adherent mucus gel layer of rat. Forty rats were divided randomized into four groups equally, which were control group, 0.5h, lh and 2h after water immersion restraint stress groups. The gastric mucosal contact angle and the content of phospholipid in mucosal surface scraping material (SSM) of glandular stomach and gastric mucosal ulcer index were measured.     

Intestinal bile acid physiology and pathophysiology

Bile acids （BAs） have a long established role in fat di- gestion in the intestine by acting as tensioactives, due to their amphipatic characteristics. BAs are reabsorbed very efficiently by the intestinal epithelium and recycled back to the liver via transport mechanisms that have been largely elucidated. The transport and synthesis of BAs are tightly regulated in part by specific plasma membrane receptors and nuclear receptors. In addition to their primary effect, BAs have been claimed to play a role in gastrointestinal cancer, intestinal in- flammation and intestinal ionic transport. BAs are not equivalent in any of these biological activities, and structural requirements have been generally identified. In particular, some BAs may be useful for cancer chemoprevention and perhaps in inflammatory bowel disease, although further research is necessary in this field. This review covers the most recent developments in these aspects of BA intestinal biology.     

Cysteamine increases expression and activity of H~1-K~ -ATPase of gastric mucosal cells in weaning piglets

AIM: To determine the in vivo and in vivo effects of cysteamine (CS) on expression and activity of H -K -ATPase of gastric mucosal cells in weaning piglets. METHODS: Eighteen litters of newborn Xinhuai piglets were employed in the in vivo experiment and allocated to control and treatment groups. From 12 d of age (D12), piglets in control group were fed basal diet, while the treatment group received basal diet supplemented with 120 mg/kg CS. Piglets were weaned on D35 in both groups. Six piglets from each group (n = 6) were slaughtered on D28 (one week before weaning), D35 (weaning), D36.5, D38, D42, and D45 (36 h, 72 h, one week and 10 d after weaning), respectively. Semi-quantitative RT-PCR was performed to determine the levels of H -K -ATPase mRNA in gastric mucosa. H -K -ATPase activity in gastric mucosa homogenate was also determined. Gastric mucosal epithelial cells from piglets through primary cultures were used to further elucidate the effect of CS on expression and activity of H -K -ATPase in vivo. Cells were treated for 20 h with 0.001, 0.01, and 0.1 mg/mL of CS (n = 4), respectively. The mRNA expression of H -K -ATPase and somatostatin (SS) as well as the H -K -ATPase activity were determined. RESULTS: in vivo, both mRNA expression and activity of H -K -ATPase in gastric mucosa of control group exhibited a trend to increase from D28 to D45, reaching a peak on D45, but did not show significant age differences. Furthermore, neither the mRNA expression nor the activity of H -K -ATPase was affected significantly by weaning. CS increased the mRNA expression of H -K -ATPase by 73%, 53%, 30% and 39% on D28 (P = 0.014), D35 (P = 0.017), D42 (P = 0.013) and D45 (P = 0.046), respectively. In accordance with the mRNA expression, H -K -ATPase activities were significantly higher in treatment group than in control group on D35 (P = 0.043) and D45 (P = 0.040). In vivo, CS exhibited a dose-dependent effect on mRNA expression and activity of H -K -ATPase. Both H -K -ATPase mRNA expression and activity in gastric mucosal epithelial cells were significantly elevated after 20 h of exposure to the moderate (H -K -ATPase expression: P=0.03; H -K -ATPase activity: P = 0.014) and high concentrations (H -K -ATPase expression: P=0.017; H -K -ATPase activity: P = 0.022) of CS. Significant increases in SS mRNA expression were observed to accompany the elevation of H -K -ATPase expression and activity induced by the moderate (P = 0.024) and high concentrations (P = 0.022) of CS. Low concentration of CS exerted no effects either on expression and activity of H -K -ATPase or on SS mRNA expression in cultured gastric mucosal epithelial cells. CONCLUSION: No significant changes are observed in mRNA expression and activity of H -K -ATPase in gastric mucosa of piglets around weaning from D28 to D45. CS increases expression and activity of gastric H -K -ATPase in vivo and in vivo. SS is involved in mediating the effect of CS on gastric H -K -ATPase expression and activity in weaning piglets.     

Association of CT perfusion imaging with plasma levels of TGF-β1 and VEGF in patients with NSCLC

Objective: To study the association of CT perfusion imaging parameters with plasma level of transforming growth factor-β1(TGF-β1) and vascular endothelial growth(VEGF) in patients with non small cell cancer(NSCLC). Methods: A total of 67 patients with NSCLC(NSCLC group) and 64 patients with benign lesion(control group) were given with CT perfusion imaging to obtain blood flow, blood volume, mean transit time, time to peal and permeability surface through CT perfusion software. The plasma levels of TGF-β1 and VEGF were tested by ELISA. The relationship between plasma levels of TGF-β1, VEGF and CT perfusion imaging parameters were analyzed. Results: CT perfusion imaging parameters and the plasma levels of TGF-β1 and VEGF of NSCLC group were significantly higher than the control group(P0.05), while CT perfusion parameters and the levels of TGF-β1 and VEGF in NSCLC group showed significant difference in different tumor node metastasis stages(P0.05). Correlation analysis showed that the level of plasma TGF-β1 and VEGF were positively correlated with blood flow, blood volume, and mean transit time(P0.05), and negatively correlated with time to peal(P0.05). There was no significant correlation between TGF-β1 and VEGF with the permeability surface. Conclusions: CT perfusion imaging parameters in patients with NSCLC is closely associated with plasma TGF-β1, VEGF and its biological characteristics. CT perfusion imaging is a convenient method to detect tumor blood perfusion.     

Growth hormone regulates intestinal ion transport through a modulation of the constitutive nitric oxide synthase-nitric oxide-cAMP pathway

AIM: Growth hormone (GH) directly interacts with the enterocyte stimulating ion absorption and reducing ion secretion induced by agonists of cAMP. Since nitric oxide (NO) is involved in the regulation of transepithelial ion transport and acts as a second messenger for GH hemodynamic effects, we tested the hypothesis that NO may be involved in the resulting effects of GH on intestinal ion transport. METHODS: Electrical parameters reflecting trans-epithelial ion transport were measured in Caco-2 cell monolayers mounted in Ussing chambers and exposed to GH and cholera toxin (CT) alone or in combination, in the presence or absence of the NO synthase (NOS) inhibitor, Nω-nitro-L-arginine methyl ester (L-NAME). Similar experiments were conducted to determine cAMP and nitrite/nitrate concentrations. NOS expression was assayed by Western blot analysis. RESULTS: L-NAME causes total abrogation of absorptive and anti-secretory effects by GH on intestinal ion transport. In addition, L-NAME was able to inhibit the GH-effects on intracellular cAMP concentration under basal conditions and in response to CT. GH induced a Ca2 -dependent increase of nitrites/nitrates production, indicating the involvement of the constitutive rather than the inducible NOS isoform, which was directly confirmed by Western blot analysis. CONCLUSION: These results suggest that the GH effects on intestinal ion transport, either under basal conditions or in the presence of cAMP-stimulated ion secretion, are mediated at an intracellular level by the activity of cNOS.     

Direct measurement of gastric H^＋／K^＋-ATPase activities in patients with or without Helicobacterpylori-associated chronic gastritis

AIM: The role of Helicobacter pylori (H pylori) infection in gastric acid secretion of patients with chronic gastritis remains controversial. This study was designed to elucidate the effect of H pylori on H+/K+-ATPase activities in gastric biopsy specimens. METHODS: Eighty-two patients with chronic gastritis who had undergone upper endoscopy were included in this study. H pylori infection was confirmed by rapid urease test and histology. Gastric H+/K+-ATPase activities and serum gastrin concentrations were measured by an enzymatic method and radioimmunoassay, respectively. For those patients who received triple therapy for eradicating H pylori, changes in the activity of gastric H+/K+-ATPase and serum gastrin levels were also measured. RESULTS: The mean gastric H+/K+-ATPase activity in Hpylori-positive group (42 patients) was slightly higher than that in Hpylori-negative group (29 patients) (169.65±52.9 and 161.38±43.85nmol P/(mg·h),respectively, P=0.301). After eradication of H pylori, the gastric H+/K+-ATPase activities slightly decreased compared to prior therapy (165.03±59.50 and 158.42±38.93 nmol P/(mg·h), respectively, P=0.805). The mean basal gastrin concentration was slightly higher in H pylori-positive patients than in H pylori-negative patients (87.92±39.65 pg/mL vs75.04±42.57 pg/mL, P= 0.228). The gastrin levels fell significantly after the eradication of H pylori. (Before treatment 87.00±30.78 pg/mL, after treatment 64.73±18.96 pg/mL, P=0.015). CONCLUSION: Gastric H+/K+-ATPase activities are not associated with H pylori status in patients with chronic gastritis.     

Effects of ethanol on antioxidant capacity in isolated rat hepatocytes

AIM: To investigate dose-response and time-course of the effects of ethanol on the cell viability and antioxidant capacity in isolated rat hepatocytes. METHODS: Hepatocytes were isolated from male adult Wistar rats and seeded into 100-mm dishes. Hepatocytes were treated with ethanol at concentrations between 0 (C), 10 (E10), 50 (E50), and 100 (E100) mmol/L (dose response) for 12, 24, and 36 h (time course). Then, lactate dehydrogenase (LDH) leakage, malondialdehyde (MDA) concentration, glutathione (GSH) level, and activities of glutathione peroxidase (GPX), glutathione reductase (GRD), superoxide dismutase (SOD), and catalase (CAT) were measured. RESULTS: Our data revealed that LDH leakage was significantly increased by about 30% in group E100 over those in groups C and E10 at 24 and 36 h, The MDA concentration in groups C, E10 and E50 were significantly lower than that in group E100 at 36 h. Furthermore, the concentration of MDA in group E100 at 36 h was significantly higher by 4.5- and 1.7-fold, respectively, than that at 12 and 24 h. On the other hand, the GSH level in group E100 at 24 and 36 h was significantly decreased, by 32% and 28%, respectively, compared to that at 12 h. The activities of GRD and CAT in group E100 at 36 h were significantly less than those in groups C and E10. However, The GPX and SOD activities showed no significant change in each group. CONCLUSION: These results suggest that longtime incubation with higher concentration of ethanol (100 mmol/L) decreased the cell viability by means of reducing GRD and CAT activities and increasing lipid peroxidation.     

Ectopic ATP synthase in endothelial cells:a novel cardiovascular therapeutic target

ATP synthase(ATPS) produces ATP in cells and is found on the inner membrane of mitochondria or the cell plasma membrane.In this presentation, we will briefly summarize the functions of ecto-ATPS in vascular endothelial cells(ECs).Ecto -ATPS is involved in adenosine metabolism on the cell surface through its ATP generation or hydrolysis activity.The ATP/ADP generated by the enzyme on the plasma membrane can bind to P2X/P2Y receptors and activate the related signaling pathways to regulate endothelial function.The-chain of ectopic ATP synthase(ATPS) on the EC surface can recruit inflammatory cells and activate cytotoxic activity to damage ECs and induce vascular inflammation.Angiostatin and other angiogenesis inhibitors can have anti-angiogenic functions by inhibiting ecto-ATPS on ECs.Ecto-ATPS on ECs is also a receptor for apoA-Ⅰ, the acceptor of cholesterol efflux,which implies the involvement in cholesterol metabolism.The main talk will focus on our recent study about shear stress regulated membrane translocation of ATPS in ECs and the consequent interaction with T lymphocytes, which caused endothelial activation.We found that laminar flow decreased level of membrane-bound ATPS(ecto-ATPS) and depleted membrane cholesterol level in ECs.In contract,oscillatory flow increased endothelial ecto-ATPS? and membrane cholesterol levels.Incubating ECs with cholesterol or depleting cellular cholesterol could mimic the effect of oscillatory or laminar flow,respectively.Knockdown of caveolin-1 expression by siRNA prevented ATPS translocation in response to shear stress.Importantly, oscillatory flow elevated the number of T cells binding to ECs,and effect that could be blocked by anti-ATPS antibody;laminar flow significantly decreased this attachment.Furthermore,the interaction of T cells and ATPS membrane translocation was elevated in the inner curvature of the aortic arch of apoE-/- mice fed a high-fat diet. Thus,our study provided the first evidence that disturbed flow and hypercholesterolemia synergistically promote T-l     

Therapeutic plasma exchange in patients with hyperlipidemic pancreatitis

AIM: To clarify the effectiveness of plasma exchange by comparing the mortality and morbidity before and after the intervention of plasma exchange.METHODS: Plasma exchange has been available as an optional therapy for hyperlipidemic pancreatitis since August 1999 in our hospital. The patients were assorted into 2 groups (group I: before August 1999 and group II: after August1999). Group I consisted of 34 patients (before the availability of plasma exchange). Group II consisted of 60 patients (after the availability of plasma exchange).Twenty patients in group II received plasma exchange after giving their consent. The mortality and morbidity were compared between group I and group II. Furthermore,the patients with severe hyperlipidemic pancreatitis (Ranson‘s score≥3) were analyzed separately. The mortality and morbidity were also compared between those receiving plasma exchange (group A) and those who did not receive plasma exchange (group B).RESULTS: There was no statistical difference in the mortality, systemic and local complications between group I and group II. When the patients with severe hyperlipidemic pancreatitis were analyzed separately, there was no statistical difference between group A and group B.CONCLUSION: Plasma exchange can not ameliorate the overall mortality or morbidity of hyperlipidemic pancreatitis.The time of plasma exchange might be the critical point. If patients with hyperlipidemic pancreatitis can receive plasma exchange as soon as possible, better result may be predicted.Further study with more cases is needed to clarify the role of plasma exchange in the treatment of hyperlipidemic pancreatitis.     

Celecoxib enhances the detoxification of diethylnitrosamine in rat liver cancer

AIM： To study the effect of celecoxib （CXB） on diethylnitrosamine activation through the regulation of cytochrome P450 in a hepatocarcinogenesis model.METHODS： Six-week-old male Sprague-Dawley rats were randomly divided into five groups, a non-treated group （NT）, a diethylnitrosamine-treated group （DEN）, a DEN＋CXB-treated group （DEN＋CXB）,and CXB 8 d-treated and CXB 32 d-treated groups. The effects of celecoxib on the enzymatic activities of CYP1A1, 2A, 2B1/2, and 2E1 were assessed in hepatic microsomes 24 h after DEN administration.Changes in CYPIA1 and CYP2B1/2 protein expression were also evaluated. The rate of DEN metabolism was measured by the production of the deethylation metabolite acetaldehyde, and the denitrosation metabolite nitrite.RESULTS： DEN＋CXB administration produced a significant increase in the enzymatic activities ofCYP2B1/2 and 1A1, whereas it did not change the activities of CYP2A and 2E1, compared to that of the DEN group. CXB treatment for eight days did not produce a significant effect on enzymatic activity when compared to the NT group; however, when it was administered for prolonged times （CXB 32 d group）,the enzymatic activities were increased in a similar pattern to those in the DEN＋CXB group. The observed increase in the enzymatic activities in the DEN＋CXB group was accompanied by an increase in the CYP2B1/2 protein levels; no changes were observed in the levels of CYPIA1. In vitro, CXB increased the denitrosation of DEN, a pathway of metabolic detoxification. The addition of SKF-525A, a preferential inhibitor of CYP2B, abrogated the denitrosation of DEN.CONCLUSION： These results suggest that the mechanism of action of CXB involves enhancement of the detoxification of DEN by an increasing denitrosation via CYP2B1/2.     

Therapeutic plasma exchange in patients with hyperlipidemic pancreatitis

AIM:To clarify the effectiveness of plasma exchange bycomparing the mortality and morbidity before and afterthe intervention of plasma exchange.METHODS:Plasma exchange has been available as anoptional therapy for hyperlipidemic pancreatitis since August1999 in our hospital.The patients were assorted into 2 groups(group Ⅰ:before August 1999 and group Ⅱ:after August1999).Group Ⅰ consisted of 34 patients(before theavailability of plasma exchange).Group Ⅱ consisted of60 patients(after the availability of plasma exchange).Twenty patients in group Ⅱ received plasma exchange aftergiving their consent.The mortality and morbidity werecompared between group Ⅰ and group Ⅱ.Furthermore,the patients with severe hyperlipidemic pancreatitis(Ranson's score≥3)were analyzed separately.Themortality and morbidity were also compared between thosereceiving plasma exchange(group A)and those who didnot receive plasma exchange(group B).RESULTS:There was no statistical difference in themortality,systemic and local complications between groupⅠ and group Ⅱ.When the patients with severe hyperlipidemicpancreatitis were analyzed separately,there was nostatistical difference between group A and group B.CONCLUSION:Plasma exchange can not ameliorate theoverall mortality or morbidity of hyperlipidemic pancreatitis.The time of plasma exchange might be the critical point.Ifpatients with hyperlipidemic pancreatitis can receive plasmaexchange as soon as possible,better result may be predicted.Further study with more cases is needed to clarify the roleof plasma exchange in the treatment of hyperlipidemicpancreatitis.     

Na~+/HCO_3~- cotransporter is expressed on β and α cells during rat pancreatic development

AIM To determine the expression and localization of the electrogenic Na~+/HCO_3~- cotransporter(NBC1) in rat pancreas during development. METHODS The rat pancreas from postnatal and embryos removed from the uterus of pregnant rats that had been sacrificed by CO2 asphyxiation were used. Rat pancreas from embryonic day(E) 15.5 and E18.5 rat embryos was isolated under a stereomicroscope. Rat pancreas from postnatal(P) days 0, 7, 14, 21 and adult was directly isolated by the unaided eye. The RT-PCR analysis of the NBC1 specific region on rat pancreastissues from different developmental stages. The two antibodies which target the NBC1 common COOHterminal region and NH2-terminal region detected a clear band of about 145 k Da in the Western blot analysis. The localization of NBC1 was examined by immuno-fluorescence detection. RESULTS The results revealed the first peak of NBC1 expression at E18.5 and the second peak at P14. Meanwhile, the low NBC1 expression occurred at P7 and adult stages. Our results demonstrated, for the first time, the presence of NBC1 in the plasma membrane of β and α cells, as well as in the basolateral membrane of acinar cells of the rat pancreas at different stages of development. CONCLUSION The data strongly suggests that NBC1 is diversely expressed in the pancreas at different developmental stages, where it may exert its functions in pancreatic development especially islet cell growth through HCO_3~- transport and pH regulation.