八肽胆囊收缩素与血管紧张素Ⅱ在拮抗大鼠吗啡镇痛中的协同作用

以往的研究表明，八肽胆囊收缩素（CCK－8）和血管紧张素Ⅱ（AⅡ）均为有效的抗阿片物质。大鼠脑室（i．C．V．）注射CCK－8或AⅡ均能拮抗吗啡的镇痛作用。本研究的目的是观察CCK－8与AⅡ在桔抗吗啡镇痛时是否相互协同。在给大鼠皮下注射吗啡10min后，再i．c．v．单独注射CCK－8或AⅡ，或同时注射二者不同剂量和不同比例的混合物。结果表明，联合应用CCK－8与AⅡ所产生的桔抗吗啡镇痛的作用明显大于单独使用CCK－8或AⅡ。应用两因素重复设计的方差分析对结果进行统计学处理，证实CCK－8和AⅡ在一定的比例范围内联合应用，确实能够协同拮抗吗啡的镇痛作用。

Adaptive cytoprotection through modulation of nitric oxide in ethanol-evoked gastritis

AIM: To assess the mechanisms of protective action by different mild irritants through maintenance of gastric mucosal integrity and modulation of mucosal nitric oxide (NO) in experimental gastritis rats.METHODS: Etcher 200 mL/L ethanol, 50 g/L NaG or 0.3 mol/L HCl was pretreated to normal or 800 mL/L ethanol-induced acute gastritis Sprague-Dawley rats before a subsequent challenge with 500 mL/L ethanol. Both macroscopic lesion areas and histological damage scores were determined in the gastric mucosa of each group of animals. Besides,gastric mucosal activities of NO synthase isoforms and of superoxide dismutase, along with mucosal level of leukotriene (LT)C4 were measured.RESULTS: Macroscopic mucosal damages were protected by 200 mL/L ethanol and 50 g/L NaCI in gastritis rats.However, although 200 mL/L ethanol could protect the surface layers of mucosal cells in normal animals (protection attenuated by NG-nitro-L-arginine methyl ester), no cytoprotection against deeper histological damages was found in gastritis rats. Besides, inducible NO synthase activity was increased in the mucosa of gastritis animals and unaltered by mild irritants. Nevertheless, the elevation in mucosal LTC4 level following 500 mL/L ethanol administration and under gastritis condition was significantly reduced by pretreatment of all three mild irritants in both normal and gastritis animals.CONCLUSION: These findings suggest that the aggravated 500 mL/L ethanol-evoked mucosal damages under gastritis condition could be due to increased inducible NO and LTC4 production in the gastric mucosa. Only 200 mL/L ethanol is truly 'cytoprotective' at the surface glandular level of nongastritis mucosa. Furthermore, the macroscopic protection of the three mild irritants involves reduction of LTC4 level in both normal and gastritis mucosa, implicating preservation of the vasculature.

Metabolic syndrome is directly associated with gamma glutamyl transpeptidase elevation in Japanese women

AIM: This study aimed to determine whether metabolic syndrome is directly or indirectly, through fatty liver, associated with elevated gamma-glutamyl transpeptidase (GGT) levels in Japanese women. METHODS: From 4 366 women who received their annual health check-up, 4211 women were selected for analysis. All 4211 women were negative for both hepatitis B surface antigen and antibody to hepatitis C virus. Clinical and biochemical variables were examined by using univariate and multivariate analysis. RESULTS: A raised GGT level (>68 IU/L) was seen in 258 (6.1%) of the 4 211 women. In univariate analysis, all variables examined (age, body mass index, blood pressure, hemoglobin concentration, fasting blood glucose, glycosylated hemoglobin A1c, cholesterol, triglyceride, and uric acid) were associated with the elevated GGT level, whereas in multivariate analysis, four variables (age ≥ 50 yr, hemoglobin ≥14 g/dL, triglyceride ≥150 mg/dL, and presence of diabetes) were significantly and independently associated with raised GGT level. Clinical variables predicting the presence of ultrasonographic evidence of fatty liver were also examined by multivariate analysis; four variables were associated with the presence of fatty liver: BMI = 25 kg/m^2, hemoglobin ≥14 g/dL, triglyceride ≥150 mg/dL, and uric add ≥7 mg/dL. There was no significant association between the raised GGT level and the presence of fatty liver. Hypertriglyceridemia was significantly and independently associated with both the raised GGT level and the presence of fatty liver. CONCLUSION: Metabolic syndrome seemed to be directly, not indirectly through fatty liver, associated with the raised GGT level in ]apanese women.

Expression and activities of three inducible enzymes in the healing of gastric ulcers in rats

AIM: To explore the roles of nitric oxide synthase (NOS),heme oxygenase (HO) and cyclooxygenase (COX) in gastric ulceration and to investigate the relationships of the expression and activities of these enzymes at different stages of gastric ulceration.METHODS: Gastric ulcers (kissing ulcers) were induced by luminal application of acetic acid. Gastric tissue samples were obtained from the ulcer base, ulcer margin, and nonulcerated area around the ulcer margin at different time intervals after ulcer induction. The mRNA expression and protein levels of inducible and constitutive isoforms of NOS,HO and COX were analyzed with RT-PCR and Western blotting methods. The activities of the total NOS, inducible NOS (iNOS), HO, and COX were also determined.RESULTS: Differential expression of inducible iNOS, HO-1and COX-2 and enzyme activities of NOS, HO and COX were found in the gastric ulcer base. High iNOS expression and activity were observed on day 1 to day 3 in severely inflamed ulcer tissues. Maximum expressions of HO-1 and COX-2 and enzyme activities of HO and COX lagged behind that of iNOS,and remained at high levels during the healing phase.CONCLUSION: The expression and activities of inducible NOS, HO-1 and COX-2 are found to be correlated to different stages of gastric ulceration. Inducible NOS may contribute to ulcer formation while HO-1 and COX-2 may promote ulcer healing.

Neither gastric topological distribution nor principle virulence genes of Helicobacter pylori contributes to clinical outcomes

AIM: Studies on Helicobacter pylori (H pylon) and gastroduodenal diseases have focused mainly on the distal sites of the stomach, but relationship with the gastric cardia is lacking. The aim of this study is to determine if the gastric topology and genotypic distribution of Hpyloriwere associated with different upper gastrointestinal pathologies in a multiethnic Asian population. METHODS: Gastric biopsies from the cardia, body/corpus and antrum were endoscoped from a total of 155 patients with dyspepsia and/or reflux symptoms, with informed consent. H pylori isolates obtained were tested for the presence of 26kDa, ureC, cagA, vacA, iceA1, iceA2 and babA2 genes using PCR while DNA fingerprints were generated using random amplification polymorphic DNA (RAPD). RESULTS: Hpyloriwas present in 51/155 (33%) of patients studied. Of these, 16, 15 and 20 were isolated from patients with peptic ulcer diseases, gastroesophageal reflux diseases and non-ulcer dyspepsia, respectively. Of the Hpyloripositive patients, 75% (38/51) had Hpyloriin all three gastric sites. The prevalence of various genes in the H pylori isolates was shown to be similar irrespective of their colonization sites as well as among the same site of different patients. The RAPD profiles of H pylori isolates from different gastric sites were highly similar among intra-patients but varied greatly between different patients. CONCLUSION: Topographic colonization of H pylori and the virulence genes harboured by these isolates have no direct bearing to the clinical state of the patients. In multiethnic Singapore, the stomach of each patient is colonized by a predominant strain of H pylori，irrespective of the clinical diagnosis.

Temporal expression of hepatic inducible nitric oxide synthase in liver cirrhosis

AIM: Nitric oxide (NO) has been implicated in the pathogenesis of liver cirrhosis. We have found inducible nitric oxide synthase (iNOS) can be induced in hepatocytes of cirrhotic liver. This study further investigated the temporal expression and activity of hepatic iNOS in cirrhosis development.METHODS: Cirrhosis was induced in rats by chronic bile duct ligation (BDL). At different time points after the operation,samples were collected to examine NO concentration, liver function, and morphological changes. Hepatocytes were isolated for determination of iNOS mRNA, protein and enzymatic activity.RESULTS: Histological examination showed early cirrhosis 1-2 wk after BDL, with advanced cirrhosis at 3-4 wk.Bilirubin increased dramatically 3 d after BDL, but decreased by 47% on d 14. Three weeks after BDL, it elevated again. Systemic NO concentration did not increase significantly until 4 wk after BDL, when ascites developed.Hepatocyte iNOS mRNA expression was identified 3 d after BDL, and enhanced with time to 3 wk, but reduced thereafter. iNOS protein showed a similar pattern to mRNA expression. iNOS activity decreased from d 3 to d 7, but increased again thereafter till d 21.CONCLUSION: Hepatic iNOS can be induced in the early stage, which increases with time as cirrhosis develops. Its enzymatic activity is significantly correlated with protein expression and histological alterations of the liver, but not with systemic NO levels, nor with absolute values of liver function markers.

Differential CI^-and HCO_3^- mediated anion secretion by different colonic cell types in response to tetromethylpyrazine

AIM: Colonic epithelium is known to secrete both CI- and HCO3, but the secretory mechanisms of different colonic cell types are not fully understood. The present study aimed to investigate the differential activation of Cl-and HCO3 secretion by tetramethylpyrazine (TMP) in human crypt-like cell line, T84, and villus-like cell line, Caco-2, in comparison to the TMP-induced secretory response in freshly isolated rat colonic mucosa. METHODS: Colonic epithelial anion secretion was studied by using the short circuit current (Isc) technique. RT-PCR was used to examine the expression of Na^+-HCO3-cotranspoter in different epithelial cell types. RESULTS: TMP produced a concentration-dependent Isc which was increase in both T84 and Caco-2 cells. When extracellular CI was removed, TMP-induced Isc was abolished by 76.6% in T84 cells, but not in Caco-2 cells. However, after both CI and HCO3- were removed, TMP-induced Isc in Caco-2 cells was reduced to 10%. Bumetanide, an inhibitor of Na^+-K^+-Cl-cotranspoter, inhibited the TMP-induced Isc by 96.7% in T84 cells, but only 47.9% in Caco-2 cells. In the presence of bumetanide and 4, 4'-diisothiocyanostilbene-2, 2'-disulfonic acid, an inhibitor of Na^+-HCO3- cotransporter, inhibited the TMP-induced current in Caco-2 cells by 93.3% .In freshly isolated rat colonic mucosa, TMP stimulated distinct Isc responses similar to that observed in T84 and Caco-2 cells depending on the concentration used. RT-PCR revealed that the expression of Na^+-HCO3- cotransporter in Caco-2 cells was 4-fold more greater than that in T84 cells. CONCLUSION: TMP exerts concentration-dependent differential effects on different colonic cell types with stimulation of predominant Cl- secretion by crypt cells at a lower concentration, but predominant HCO3- secretion by villus cells at a higher concentration, suggesting different roles of these cells in colonic Cl and HCO3 secretion.

Management of erectile dysfunction: barriers faced by general practitioners

Aim: To explore the barriers faced by general practitioners (GPs) in the management of patients with erectile dysfunction (ED). Methods: This was a qualitative analysis of focus group discussions and in-depth inter views involving 28 Malaysian GPs. Results: GPs' perception of ED being not a serious condition was a major determinant of their prescribing practice. Doctor's age (younger), gender (female), short consultation time and lack of experience were cited as barriers. The GPs' prescribing habits were heavily influenced by the feedback from the first few patients under treatment, the uncertainty of etiology of ED without proper assessment and the profit margin with bulk purchase. Other barriers include Patients' coexisting medical conditions, older age, lower socio-economic status, unrealistic expectations and inappropriate use of the anti-impoteneet drugs. Cardiovascular side effects and cost were two most important drug barriers. Conclusion: The factors influencing the management of ED among the general practitioners were multiple and complex. An adequate understanding of how these factors (doctors, patients and drugs) interact can assist in the formulation and implementation of strategies that encourage GPs to identify and manage ED patients.

Expression of Lewis^b blood group antigen in Helicobacter pylori does not interfere with bacterial adhesion property

AIM: The finding that some Helicobacterpyloristrains expressLewis b (Leb) blood group antigen casts a doubt on the roleof Leb of human gastric epithelium being a receptor for-H.pylori. The aim of this study was to determine if expressionof Leb in H. Pyloriinterferes with bacterial adhesion property.METHODS: Bacterial adhesion to immobilized Leb onmicrotitre plate was performed in 63-H. Pyloristrains obtainedfrom Singapore using in vitro adherence assay. Expression ofLewis blood group antigens was determined by ELISA assay.RESULTS: Among 63 H. Pyloristrains, 28 expressed Lebantigen. In vitro adhesion assay showed that 78.6 % (22/28) of Leb-positive and 74.3 % (26/35) of Leb-negative-H.pyloriisolates were positive for adhesion to immobilized Lebcoated on microtitre plate (P＝0.772). In addition, blockingof H. Pylori Leb by prior incubation with anti-Leb monoclonalantibody did not alter thebinding of the bacteria to solid-phase coated Leb.CONCLUSION: The present study suggests that expressionof Leb in H. Pyloridoes not interfere with the bacterialadhesion property. This result supports the notion that Lebpresent on human gastric epithelial cells is capable of beinga receptor for H.pylori.

Do patients with non-ulcer dyspepsia respond differently to Helicobacter pylorieradication treatments from those with peptic ulcer disease? A systematic review

AIM: It is controversial whether patients with non-ulcer dyspepsia (NUD) respond differently to Helicobacter pylori(Hpylon) eradication treatment than those with peptic ulcer disease (PUD). To review the evidence for any difference in Hpylorieradication rates between PUD and NUD patients.METHODS: A literature search for full articles and meeting abstracts to July 2004 was conducted. We included studies evaluating the efficacy of a proton pump inhibitor(P) or ranitidine bismuth citrate (RBC) plus two antibiotics of clarithromycin (C), amoxicillin (A), metronidazole (M),or P-based quadruple therapies for eradicating the infection.RESULTS: Twenty-two studies met the criteria. No significant difference in eradication rates was found between PUD and NUD patients when treated with 7-d RBCCA, 10-d PCA or P-based quadruple therapies. When the 7-d PCA was used, the pooled H pylori eradication rate was 82.1% (431/525) and 72.6% (448/617) for PUDand NUD patients, respectively, yielding a RR of 1.15(95%CI 1.01-1.29). However, the statistically significant difference was seen only in meeting abstracts, but not in full publications.CONCLUSION: There is no convincing evidence to suggest that NUD patients respond to Hpylori eradication treatments differently from those with PUD, although a trend exists with the 7-d PCA therapy.

Modulation of human enteric epithelial barrier and ion transport function by Peyer's patch lymphocytes

AIM: To investigate the role of Peyer's patch lymphocytes in the regulation of enteric epithelial barrier and ion transport function in homeostasis and host defense. METHODS: Mouse Peyer's patch lymphocytes were co-cultured with human intestinal epithelial cell line Caco-2 either in the mixed or separated (isolated but permeable compartments) culture configuration. Barrier and transport functions of the Caco-2 epithelial monolayers were measured with short-circuit current (Isc) technique. Release of cytokines was measured by enzyme-linked immunosorbent assay (ELISA) and cytokine mRNA expression was analyzed by semi-quantitative RT-PCR. Barrier and iontransport functions of both culture conditions following exposure to Shigella lipopolysaccharide (LPS) were also examined. RESULTS: The transepithelial resistance (TER) of the epithelial monolayers co-cultured with Peyer's patch lymphocytes was maintained whereas that of the Caco-2 monolayers alone significantly decreased after eight days in culture. The forskolin-induced anion secretion, in either absence or presence of LPS, was significantly suppressed in the both co-cultures as compared with the Caco-2 cells alone. Furthermore, only the mixed co-culture condition induced the expression and release of mIL-6 from Peyer's patch lymphocytes, which could be further enhanced by LPS. However, both co-culture conditions suppressed expression and release of epithelial hIL-8 under the unstimulated conditions, while the treatment with LPS stimulated their hIL-8 expression and release. CONCLUSION: Peyer's patch lymphocytes may modulate intestinal epithelial barrier and ion transport function in homeostasis and host defense via cell-cell contact and cytokine signaling.

Improvement of barrier function and stimulation of colonic epithelial anion secretion by Menoease Pills

AIM: Menoease Pills(MP)1 a Chinese medicine-based new formula for postmenopausal women, has been shown to modulate the endocrine and immune systems. The present study investigated the effects of MP and one of its active ingredients, ligustrazine, on epithelial barrier and ion transport function in a human colonic cell line, T84.METHODS: Colonic transepithelial electrophysiological characteristics and colonic anion secretion were studied using the short circuit current (Isc) technique. RT-PCR was used to examine the expression of cytoplasmic proteins associated with the tight junctions, ZO-l(zonula occludens-1) and ZO-2 (zonula occludens-2).RESULTS: Pretreatment of T84 cells with MP (15 μg/mL) for 72 h significantly increased basal potential difference,transepithelial resistance and basal ISC. RT-PCR results showed that the expressions of ZO-land ZO-2 were significantly increased after MP treatment, consistent with improved epithelial barrier function. Results of acute stimulation showed that apical addition of MP produced a concentrationdependent (10-5 000 μg/mL, EC50 = 293.9 μg/mL) increase in ISC. MP-induced ISC was inhibited by basolateral treatment with bumetanide (100 μmol/L), an inhibitor of the Na^+-K^+-2Cl^- cotransporter, apical addition of Cl^- channel blockers, diphenylamine-2, 2'-dicarboxylic acid (1mmol/L) or glibenclamide (1 retool/L), but not 4, 4'-diisothiocyanostilbene-2, 2'-disulfonic acid or epithelial Na+ channel blocker,amiloride. The effect of MP on ZOo1 and ZO-2was mimicked by Ligustrazine and the ligustrazine-induced ISC was also blocked by basolateral application of bumetanide and apical addition of diphenylamine-2, 2'-dicarboxylic acid or glibenclamide, and reduced by a removal of extracellular Cl^-.CONCLUSION: The results of the present study suggest that MP and lligustrazine may improve epithelial barrier function and exert a stimulatory effect on colonic anion secretion, indicating the potential use of MP and its active ingredients for improvement of GI tract host defense and alleviation of constipation often seen in the elderly.

Effect of tetramethylpyrazine on exocrine pancreatic and bile secretion

AIM: To investigate the effect of tetramethylpyrazine (ligustrazine, TMP) on the secretion of exocrine pancreas (and biliary).METHODS: In in vivo study, we investigated the effect of TMP on the secretion of pancreatic-bile juice (PBJ) in rats.Using human pancreatic duct cell line, CAPAN-1, combined with the short-circuit current (ISC) technique we further studied the effect of TMP on the pancreatic anion secretion.RESULTS: Administration of TMP (80 mg/kg, ip) significantly increased the secretion of PBJ (P<0.05), but the pH of PBJ and the secretion of pancreatic protein were not significantly affected. Basolateral addition of TMP produced a dosedependent increase in ISC(EC50=1.56 mmol/L), which contained a fast transient ISC response followed by a slow decay. Apical application of Cl- channel blockers, DPC (1 mmol/L),decreased the response by about 67.1% (P<0.001), whereas amiloride (100 μmol/L), a epithelial sodium channel blockers,had no effect. Removal of extracellular HCO3- abolished TMP-induced increase in ISC by about 74.4 % (P<0.001),but the removal of external Cl- did not. Pretreatment with phosphodiesterase inhibitor, TBMX(0.5 mmol/L), decreased the TMP-induced ISC by 91% (P<0.001).CONCLUSION: TMP could stimulate the secretion of PBJ,especially pancreatic ductal HCO3- secretion via cAvlp or cGMP-dependent pathway. It need further study to investigate the roles of cAMP or cGMP in the effect of TMP on the secretion of exocrine pancreas.

Head-to-head comparison of H_2-receptor antagonists and proton pump inhibitors in the treatment of erosive esophagitis: A meta-analysis

AIM: To systematically evaluate the efficacy of H2-receptor antagonists (H2RAs) and proton pump inhibitors in healing erosive esophagitis (EE).METHODS: A meta-analysis was performed. A literature search was conducted in PubMed, Medline, Embase, and Cochrane databases to include randomized controlled head-to-head comparative trials evaluating the efficacy of H2RAs or proton pump inhibitors in healing EE. Relative risk (RR) and 95% confidence interval (CI) were calculated under a random-effects model.RESULTS: RRs of cumulative healing rates for each comparison at 8 wk were: high dose vs standard dose H2RAs,1.17 (95%CI, 1.02-1.33); standard dose proton pump inhibitors vsstandard dose H2RAs, 1.59 (95%CI, 1.44-1.75);standard dose other proton pump inhibitors vs standard dose omeprazole, 1.06 (95%CI, 0.98-1.06). Proton pump inhibitors produced consistently greater healing rates than H2RAs of all doses across all grades of esophagitis, including patients refractory to H2RAs. Healing rates achieved with standard dose omeprazole were similar to those with other proton pump inhibitors in all grades of esophagitis.CONCLUSION: H2RAS are less effective for treating patients with erosive esophagitis, especially in those with severe forms of esophagitis. Standard dose proton pump inhibitors are significantly more effective than H2RAs in healing esophagitis of all grades. Proton pump inhibitors given at the recommended dose are equally effective for healing esophagitis.

Regulation of alternative splicing of Bcl-x by IL-6,GM-CSF and TPA

The splicing of many alternative exons in the precursor messenger RNA (pre-mRNA) is regulated by extracellular factors but the underlying molecular bases remain unclear. Here we report the differential regulation of Bcl-x pre-mRNA splicing by extracellular factors and their distinct requirements for pre-mRNA elements. In K562 leukemia cells, treatment with interleukin-6 (IL-6) or granulocyte-macrophage colony stimulating factor (GM-CSF) reduced the proportion of the Bcl-xL variant mRNA while treatment with 12-O-tetradecanoylphorbol 13-acetate (TPA) had no effect. In U251 glioma cells, however, TPA efficiently increased the Bcl-xL level. These regulations were also seen for a transfected splicing reporter mini-gene. Further analyses of deletion mutants indicate that nucleotides 1-176 of the downstream intron are required for the IL-6 effect, whereas additional nucleotides 177-284 are essential for the GM-CSF effect. As for the TPA effect, only nucleotides 1-76 are required in the downstream intron. Thus, IL-6, GM-CSF and TPA differentially regulate Bcl-x splicing and require specific intronic pre-mRNA sequences for their respective effects.

Risk Factors for Cardiovascular Disease in Obese and Normal School Children: Association of Insulin with Other Cardiovascular Risk Factors

Objective To investigate the level of insulin and other known cardiovascular risk factors in school children and their association with obesity.Design Cross-sectional study.Subjects 123 normal and 116 obese school children categorized by weight-for-height,mean age. 10.2 and 10.5 years old respectively.Measurements Family histories of diseases by questionnaires; blood pressure (BP) and waist and hip circumferences by measurements; fasting blood for glucose, insulin, total cholesterol, HDL-cholesterol and triglycerides.Results The numbers of boys in the normal and obese group were 65 and 58, those of the girls, 53 and 63 respectively. The obese group was more likely to have family histories of obesity, high blood pressure and diabetes; had significantly greater waist-hip-ratio (WHR), higher systolic and diastolic BP, lower HDL-cholesterol, higher triglyceride and fasting insulin levels (with fasting blood sugar in the normal range) than the normal weight group. In a crude analysis, insulin levels were positiveIy correlated with obesity, systolic BP, WHR, age and triglycerides and negatively associated with male gender and HDLcholesterol. After adjustment using multiple regression, only obesity status, age, gender and triglycerides still remained significantly associated with insulin level. Limitation of utilizing family disease history report for identification of children at risk was discussed.Conclusion These findings suggest that risk to coronary heart disease and hypertension through insulin resistance already operates in school-aged children

Opisthorchiasis-associated biliary stones:Light and scanning electron microscopic study

AIM: Biliary stones are frequently encountered in areas endemic for opisthorchiasis in Thailand. The present study was to descdbe the prevalence and pathogenesis of these stones. METHODS: Gallstones and/or common bile duct stones and bile specimens from 113 consecutive cholecystectomies were included. Bile samples, including sludge and/or microcalculi, were examined for Opisthorchis viverrini eggs,calcium and bilirubin. The stones were also processed for scanning electron microscopic (SEM) study. RESULTS: Of the 113 cases, 82 had pigment stones, while one had cholesterol stones. The other 30 cases had no stones. Most of the stone cases (76%, 63/83) had multiple stones, while the remainder had a single stone. Stones were more frequently observed in females. Bile examination was positive for O.viverrini eggs in 50% of the cases studied. Aggregates of calcium bilirubinate precipitates were observed in all cases with sludge. Deposition of calcium bilirubinate on the eggshell was visualized by special staining. A SEM study demonstrated the presence of the parasite eggs in the stones. Numerous crystals, morphologically consistent with calcium derivatives and cholesterol precipitates, were seen. CONCLUSION: Northeast Thailand has a high prevalence of pigment stones, as observed at the cholecystectomy, and liver fluke infestation seems involved in the pathogenesis of stone formation.

Ultracytochemical localization of H+-adenosine triphosphatase activity in autophagic vacuoles induced by vinblastine in rat liver

H^-adenosine triphosphatase (H^+-ATPase) activity was demonstrated cytochemically in autophagic vacuoles(AVs) of rat hepatocytes using a modification of the method for the demonstration of neutral p-nitrophenyl phosphatase(p-NPPase) activity[1].When an inhibitor of H^+-ATPase,N-ethylmaleimide (NEM) or 4,4'-diisothiocyanostilbene-2,2'disulfonic acid,disodium salt (DIDS) was included in the incubation medium the enyzme activity was abolished indicating that p-NPPase demonstrated in this study represents H^+-ATPase.Autophagy was induced by a single intraperitoneal injection of vinblastine sulfate(VBL).The number of AVs increased remarkably in hepatocytes from 40 min after VBL treatment.H^+-ATPase activity was observed mainly on the membranes of lysosomes and AVs.However,early forms of AVs containing only incompletely digested material showed no H^+-ATPase activity.Most AVs revealing a positive reaction seemed to be in advanced stages of development.Acid phosphatase acticity was demonstrable in mature but not in early forms of AVs.The present investigation showed that membranes of advanced stage AVs possess an H^+-ATPase which may be derived from lysosomal membranes.