Roles of sphincter of Oddi motility and serum vasoactive intestinal peptide,gastrin and cholecystokinin octapeptide

AIM:To investigate roles of sphincter of Oddi(SO)motility played in pigment gallbladder stone formation in model of guinea pigs.METHODS:Thirty-four adult male Hartley guinea pigs were divided randomly into two groups:the control group and pigment stone group.The pigment stone group was divided into 4 subgroups with 6 guinea pigs each according to time of sacrifice,and were fed a pigment lithogenic diet and sacrificed after 3,6,9 and 12wk.SO manometry and recording of myoelectric activity of the guinea pigs were obtained by multifunctional physiograph at each stage.Serum vasoactive intestinal peptide(VIP),gastrin and cholecystokinin octapeptide (CCK-8)were detected at each stage in the process of pigment gallbladder stone formation by enzyme-linked immunosorbent assay.RESULTS:The incidence of pigment gallstone formation was 0%,0%,16.7%and 66.7%in the 3-,6-,9-and 12-wk group,respectively.The frequency of myoelectric activity decreased in the 3-wk group.The amplitude of myoelectric activity had a tendency to decrease but not significantly.The frequency of the SO decreased significantly in the 9-wk group.The SO basal pressure and common bile duct pressure increased in the 12-wk group(25.19±7.77 mmHg vs 40.56±11.81 mmHg,22.35±7.60 mmHg vs 38.51±11.57mmHg,P<0.05).Serum VIP was significantly elevated in the 6-and 12-wk groups and serum CCK-8 was decreased significantly in the 12-wk group.CONCLUSION:Pigment gallstone-causing diet may induce SO dysfunction.The tension of the SO increased.The disturbance in SO motility may play a role in pigment gallstone formation,and changes in serum VIP and CCK-8 may be important causes of SO dysfunction.     

Changes of gastrointestinal myoelectric activity and bile acid pool size after cholecystectomy in guinea pigs

AIM: To investigate the bile acid pool size after cholecystectomy whether or not correlated to the gastrointestinal migrating myoeiectric complex (MMC) in guinea pigs. METHODS: Gallbladder motilities were assessed before cholecystectomy. Furthermore, we continuously monitored interdigestive gastrointestinal motilities using bipolar electrodes in conscious guinea pigs before and after surgery at 4 wk in standard diet group and high cholesterol diet (cholesterol gallstone) group. Total bile acid pool sizes were measured by isotope dilution method at meantime. RESULTS: After cholecystectomy, there were parallel falls in duration of phase Ⅰ, Ⅱ, Ⅲ and MMC cycle duration but increase in amplitude in the guinea pigs with normal gallbladder function, and in the guinea pigs with cholesterol stones. However, There were not significantly differences. On the other hand, the bile acid pool was definitely small in the GS guinea pigs compared to normal guinea pigs and became slightly smaller after cholecystectomy. Similarly, bile acid in gallbladder bile, fecal bile acid was slightly increased in GS guinea pigs after cholecystectomy, to the same degree as normal. These differences, however, were not significant. CONCLUSION: It is concluded that in the guinea pigs with normal gallbladder function, and in the guinea pigs with cholesterol stones: (1) Cholecystectomy produce a similar but less marked trend in bile acid pool; and (2) MMC are linked to enterohepatic circulation of bile acids, rather than surgery, which is consistent with changes of the bile acid pool size. As a result, gastrointestinal dyskinesia is not involved in occurrence of postchole cystectomy syndrome.     

中药胆宁片治疗胆囊胆固醇结石作用机制的实验研究

[目的]探讨胆宁片对胆固醇结石豚鼠胆汁中黏蛋白及血清IL-2水平的影响.[方法]雌性豚鼠60只,体重（300±20）g,随机分为空白组、模型组、胆宁片组和熊脱氧胆酸组,每组15只;除空白组外,采用“高胆固醇致石食饵诱发法”建立豚鼠胆固醇结石模型,并于造模成功后分别对各治疗组予药物干预,胆宁片组灌服胆宁混悬液0.52 g· kg-1·d-1,熊脱氧胆酸组灌服熊脱氧胆酸混悬液0.05 g·kg-1·d-1,模型组与空白组均灌服等容量的生理盐水,8周后观察各组豚鼠一般情况、胆汁中黏蛋白及血清IL-2水平.[结果]胆宁片可显著降低豚鼠胆固醇结石成石率,并能显著降低胆囊黏蛋白及血清IL-2水平（P＜0.05,P＜0.01）.[结论]胆宁片能直接调节胆囊黏蛋白等相关促成核因子,同时能通过调节血清中IL-2间接调控胆囊黏蛋白水平,从而调控成核过程,对胆囊胆固醇结石有一定的治疗作用.     

Effect of age and sensitivity to cholecystokinin on gallstone formation in the guinea pig

The purpose of this study was to evaluate the effect of age and the role of cholecystokinin therapy on gallstone formation in guinea pigs. Guinea pigs (31 1-mo-old, 31 1-yr-old, and 23 3-yr-old) were placed on a cholelithogenic diet for 2 wk while another 10 guinea pigs of each age group remained on regular chow. Half of each group received a daily injection of cholecystokinin (0.5 nmol/kg). After 2 wk, guinea pigs were killed and the gallbladders were examined for gallstones. The concentrations of bile constituents were determined. The prevalence of gallstones was: 1-mo-old, control 0 out of 16, cholecystokinin 1 out of 15; 1-yr-old, control 3 out of 14, cholecystokinin 5 out of 16; 3-yr-old, control 10 out of 11, cholecystokinin 3 out of 8. Gallstone formation was significantly greater in 3-yr-old controls than in the two younger control groups, and cholecystokinin treatment significantly reduced the incidence of gallstones to near the level seen in younger guinea pigs. In the two younger age groups (but not in the 3-yr-old group), the cholelithogenic diet significantly reduced the concentration of bile salts in bile below that of guinea pigs on a normal diet. The cholelithogenic diet and treatment with cholecystokinin did not alter the relative compositions of bile lipids from that of guinea pigs on a normal diet in any of the three ages studied. In the second experiment we measured gallbladder emptying in response to exogenous infusion of cholecystokinin-8 (100 fmol/kg/h-100 nmol/kg/h) in the same three age groups of guinea pigs in vivo that had been maintained on regular chow. There was no difference in cholecystokinin sensitivity between the two younger age groups, but both were significantly more sensitive to cholecystokinin than the 3-yr-old guinea pigs in rate of gallbladder emptying in the dose range 1 pmol/kg/h-1 nmol/kg/h. We conclude that a major factor in the increased incidence of gallstone formation in the aged guinea pig gallstone model is decreased gallbladder emptying due to decreased gallbladder sensitivity to cholecystokinin.     

Comparison of effects of cholecystokinin and erythromycin on bile chemistry and gallstone formation in aged guinea pigs.

BACKGROUND: There has been considerable interest in gall bladder motility in recent years. We compared the effects of cholecystokinin (CCK) and erythromycin on bile chemistry and gallstone formation in aged guinea pigs. METHODS: Two groups of guinea pigs (1-mo and 3-y old; n=40 each) were studied. Each group was divided into four subgroups of 10 animals each; one subgroup received lithogenic diet, one each received CCK or erythromycin daily in addition to lithogenic diet for 4 weeks, and one received normal diet. After 4 weeks, the presence of gallstones or sludge was recorded and bile composition including concentrations of bile acid, cholesterol, lecithin and protein concentrations was studied. RESULTS: No gallstones were observed in the 1-mo-old animals. In the 3-year-old animals, 9 of 10 guinea pigs on lithogenic diet and 4 of 10 in each treatment subgroup and the normal diet subgroup developed gallstones. CCK and erythromycin had similar effects on bile chemistry and stone formation. CONCLUSIONS: Aging increases the formation of gallstones in guinea pigs. Erythromycin is as effective as CCK in reducing gallstone formation by improving gall bladder motility.     

胆胃舒颗粒对胆囊血管活性肠肽受体基因表达的影响

[目的]观察胆胃舒颗粒对胆囊血管活性肠肽(vasoactive intestinal peptide,VIP)受体基因表达的影响及预防胆囊结石的作用.[方法]雄性豚鼠90只,随机分为3组,每组30只,空白组喂养普通饲料40 g/(d·只);模型组喂养胆固醇结石诱石饲料40 g/(d·只);治疗组喂养胆固醇诱石饲料40 g/(d·只),加胆胃舒颗粒溶液1.5ml(含300mg胆胃舒颗粒)灌胃.实验2个月后观察3组胆囊结石情况、胆囊收缩功能及胆囊壁VIP受体基因表达.[结果]胆囊结石形成率:空白组3.33％(1/30),模型组92.59％(25/27),治疗组10.71％(3/28);胆囊收缩功能:空白组胆囊收缩率为(66.83± 5.34)％,模型组(43.06±4.27)％,治疗组(67.93±6.82)％;胆囊壁VIP受体基因表达:空白组0.30±0.07,模型组0.45±0.12,治疗组0.33±0.06.差异均有统计学意义(P＜0.05).[结论]胆胃舒颗粒可降低胆囊结石的形成,其作用机制可能通过降低胆囊壁VIP受体基因表达,从而加强胆囊收缩功能,促使胆汁排泄,防止胆囊结石的发生.     

Influence of fever on biliary elements of guinea pigs

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Melatonin prevents pigment gallstone formation induced by bile duct ligation in guinea pigs

Free radical-mediated oxidative stress has been implicated in the genesis of gallstone in vitro. This study was designed to examine the oxidative stress changes during pigment gallstone formation and to investigate whether melatonin (MLT) could act as a chemopreventive agent for cholelithiasis in a guinea pig model. The common bile duct of guinea pigs was ligated with or without MLT pretreatment. Animals were studied on day 7, 9, 12, and 14 after surgery. Stone and/or sludge developed in ligated guinea pigs without MLT. Fourier transform infrared spectra of the sludge showed the presence of calcium bilirubinate, whose peak height per milligram of sludge gradually increased with time after ligation. Total antioxidant activity (TAA) in bile of guinea pigs at day 14 after ligation reduced to one third of the level in sham-operated controls (P <.001). In addition, the bile of ligated guinea pigs had increased pH (P <.001), bile salts (P <.01), and malondialdehyde (MDA) (P <.05), compared to sham controls. Pretreatment of guinea pigs with MLT at a dose of 1,000 microg/kg significantly decreased the incidence of pigment gallstone formation at day 14 after ligation, as compared to no pretreatment (0/7 vs. 8/10). MLT also reverted the ligation-induced changes in biliary bile salts, pH, MDA, and TAA to control levels. These in vivo findings support a causative role of oxidative stress in the bile duct ligation-induced pigment gallstone formation. Antioxidants may prove useful in preventing pigment gallstone formation in humans.     

金茵利胆灵对豚鼠胆石症及G蛋白偶联胆汁酸受体表达的影响

目的研究金茵利胆灵对豚鼠胆囊容积和成石率与G蛋白偶联胆汁酸受体表达的影响。方法取雌性豚鼠72只,随机分为6组,每组12只,除正常对照组外其余5组给予盐酸林可霉素皮下注射建立胆石症模型。治疗组分为4组给予阿司匹林,金茵利胆灵高、中、低剂量药液灌喂,末次给药后1 h,切除胆囊测量胆囊容积,计算每组动物的胆囊内成石率。将胆囊组织进行HE染色后行显微镜观察,并行免疫组化观察阳性细胞。多组间比较采用单因素方差分析,两组间比较用LSD-t法;计数资料采用χ2检验,两组间比较调整检验水准进行比较;等级资料采用Kruskal-Wallis H检验。结果模型组成石率高于正常对照组,差异有统计学意义(P=0.00);金茵利胆灵高剂量组成石率较其他组降低。模型组胆囊大量中性粒细胞浸润,炎性改变明显;各药物治疗组中金茵高剂量组炎性改变最轻。模型组胆囊容积增加明显,与正常对照组相比差异有统计学意义(P0.01),造模效果较好;金茵利胆灵高剂量组胆囊容积相对最小,金茵利胆灵中剂量组和阿司匹林组胆囊容积相对略小,与模型组相比差异均有统计学意义(P0.01)。模型组胆囊黏膜TGR5阳性表达强,与正常对照组相比差异有统计学意义(P=0.00);金茵利胆灵高剂量组黏膜TGR5阳性表达较弱,与模型组相比差异有统计学意义(P0.01)。结论 TGR5在胆石症豚鼠胆囊黏膜的表达显著增强。金茵利胆灵可以降低胆石症豚鼠胆囊黏膜TGR5阳性表达率,可减轻胆囊炎症,减少胆石形成。     

Effects of octreotide on gallbladder pressure and myoelectric activity of Oddi sphincter in rabbits

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The preliminary experimental and clinical study of the relationship between the pigment gallstone and intestinal mucosal barrier

Aims:  To investigate the relations between the formation of pigment gallstone and the function of the intestinal mucosal barrier, as well as the underlying mechanism.
Methods:  Eighty guinea pigs were randomly divided into three groups in which they were respectively given normal diet, gallstone-causing diet, and gallstone-formation diet with a supplementary intestinal mucosal protection compound known as glutamine. The model of pigment gallstone was established after 8 weeks of dietary administration. Indices about the function of the intestinal mucosal barrier and bacterial translocation were measured. Clinical cases were divided into three groups: control, cholesterol gallstone, and pigment gallstone, where the levels of plasma diamine oxidase (DAO), plasma endotoxin and the excretion rates of technetium 99m-diethylene triamine pentaacetic acid (99mTC-DTPA) in the urine of each group were measured.
Results:  In the pigment gallstone group, the level of plasma DAO and endotoxin, the excretory ratio of lactulose and mannitol in urine, the bacterial translocation ratio in the celiac lymph nodes and the activities of β-glucuronidase increased comparing to the control group. The gallstone-formation rate for the intestinal mucosal protection group (GLN) decreased, and other indices, except the activity of β-glucuronidase, were all lower than that of gallstone-formation group. In the clinical experiment, the levels of plasma DAO and endotoxin, as well as the excretory rate of 99mTC-DTPA in urine were higher in the patients with gallstones than that in the control group.
Conclusions:  The formation of pigment gallstone was related to the abnormal function of the intestinal mucosal barrier. The abnormality in the function of the intestinal mucosal barrier probably induced the formation of gallstone by a bacterial translocation mechanism.     

Association of caveolin-3 and cholecystokinin A receptor with cholesterol gallstone disease in mice

AIM: To investigate the role of caveolin-3 (CAV3) and cholecystokinin A receptor (CCKAR) in cholesterol gallstone disease (CGD).METHODS: To establish a mouse model of CGD, male C57BL/6 mice were fed with a lithogenic diet containing 1.0% cholic acid, 1.25% cholesterol and 15% fat; a similar control group was given a normal diet. The fresh liver weights and liver-to-body weight ratio were compared between the two groups after one month. Serum lipid profile and bile composition were determined with an autoanalyzer. The Cav3 and Cckar mRNA and CAV3 and CCKAR protein levels in the liver and gallbladder were determined via real-time polymerase chain reaction and Western blot, respectively.RESULTS: Establishment of the mouse CGD model was verified by the presence of cholesterol gallstones in mice fed the lithogenic diet. Compared with mice maintained on a normal diet, those fed the lithogenic diet had significantly higher mean liver-to-body weight ratio (0.067 ± 0.007 vs 0.039 ± 0.007, P < 0.01), serum total cholesterol (4.22 ± 0.46 mmol/L vs 2.21 ± 0.11 mmol/L, P < 0.001), bile total cholesterol (1.33 ± 0.33 mmol/L vs 0.21 ± 0.11 mmol/L, P < 0.001), and bile phospholipid concentrations (3.55 ± 1.40 mmol/L vs 1.55 ± 0.63 mmol/L, P = 0.04), but lower total bile acid concentrations (726.48 ± 51.83 μmol/L vs 839.83 ± 23.74 μmol/L, P = 0.007). The lithogenic diet was also associated with significantly lower CAV3 in the liver and lower CAV3 and CCKAR in the gallbladder compared with the control mice (all P < 0.05).CONCLUSION: CAV3 and CCKAR may be involved in cholesterol gallstone disease.     

Gallbladder motor function, plasma cholecystokinin and cholecystokinin receptor of gallbladder in cholesterol stone patients

AIM: To study the interactive relationship of gallbladder motor function, plasma cholecystokinin (CCK) and cholecystokinin A receptor (CCK-R) of gallbladder in patients with cholesterol stone disease. METHODS: Gallbladder motility was studied by ultrasonography in 33 patients with gallbladder stone and 10 health subjects as controls. Plasma CCK concentration was measured by radioimmunoassay in fasting status (CCK-f) and in 30 min after lipid test meal (CCK-30). Radioligand method was employed to analyze the amount and activity of CCK-R from 33 gallstone patients having cholecystectomy and 8 persons without gallstone died of severe trauma as controls. RESULTS: The percentage of cholesterol in the gallstone composition was more than 70%. The cholesterol stone type was indicated for the patients with gallbladder stone in this study. Based on the criterion of gallbladder residual fraction of the control group, 33 gallstone patients were divided into two subgroups, contractor group (14 cases) and non-contractor group (19 cases). The concentration of CCK-30 was significantly higher in non-contractor group than that in both contractor group and control group (55.86±3.86 pmol/L vs 37.85±0.88 pmol/L and 37.95±0.74 pmol/L, P<0.01), but there was no difference between contractor group and control group. Meanwhile no significant difference of the concentration of CCK-f could be observed among three groups. The amount of CCK-R was lower in non-contractor group than those in both control group and contractor group (10.27±0.94 fmol/mg vs 24.59±2.39 fmol/mg and 22.66±0.55 fmol/mg, P<0.01). The activity of CCK-R shown as KD in non-contractor group decreased compared to that in control group and contractor group. Only was the activity of CCK-R lower in contractor group than that in control group. The ejection fraction correlated closely with the amount of CCK-R (r=0.9683, P<0.01), and the concentration of CCK-30 correlated negatively with the amount of CCK-R closely (r=-0.9627, P<0.01). CONCLUSION: The distinctive interactive relationship of gallbladder emptying, plasma CCK and CCK-R in gallbladder from this study suggested that the defect of CCK-R may be a key point leading to the impairment of gallbladder motor function and the pathogenesis of cholesterol gallstone formation may differ in two subgroups of gallstone patient, gallbladder non-contractor group or contractor group.     

Altered migrating myoelectrical complex in an animal model of cholesterol gallstone disease: the effect of erythromycin

Background—The ground squirrel on a highcholesterol diet exhibits prolonged intestinal transit, a pathogeneticfactor in cholesterol gallstone formation.
Aims—To examine the effect of a high cholesteroldiet on the characteristics of the migrating myoelectrical complex(MMC) and the potential benefit of erythromycin.
Methods—Twenty four animals received either atrace (controls) or a 1% (high) cholesterol diet. After four weeks,five bipolar jejunal and terminal ileal electrodes were implanted.Seven days later, myoelectric activity was measured in conscious,fasted animals before and after treatment with erythromycin. Biliary lipid composition was assessed.
Results—Compared with controls, animals fed thehigh cholesterol diet exhibited a prolonged MMC cycle period (70 (6)versus 83 (3) minutes; p<0.05), whereas MMC migration velocity and the proportions of the MMC represented by phases I, II, and III were unchanged. Oral erythromycin significantly shortened the MMC cycle period in animals on the control and high cholesterol diet by 59% and54% respectively, and increased the proportion of the cycle periodoccupied by phase III of the MMC in both dietary groups. Gall bladderbile became saturated with cholesterol and crystals developed in nineof 12 animals on the high cholesterol diet; controls had none.
Conclusion—Animals fed a high cholesterol diethad a prolonged MMC cycle period. This, along with diminished gallbladder motility, impairs the enterohepatic cycling of bile salts and reduces their hepatic secretion, contributing to the formation ofabnormal bile. Erythromycin initiated more frequent cycling of the MMC.Its therapeutic value in cholesterol gallstone formation warrantsfurther evaluation.

Keywords:migrating myoelectrical complex; intestinal transit; cholesterol saturation index; gallstone disease; erythromycin

     

Cholecystokinin-mediated ileal electrolyte transport in the guinea pig. Characterization of receptor subtype

Cholecystokinin (CCK) receptors are currently divided into at least two subtypes: a CCK-A subtype, responsive to the sulfated form of cholecystokinin octapeptide (CCK-8) and selectively antagonized by L-364,718, and a CCK-B subtype, which shares equal affinities for gastrin and CCK-8. In the present study the receptor subtype that mediates guinea pig ileal secretion by evaluating the potencies of CCK- and gastrin-related peptides to evoke increases in transmucosal short-circuit current was characterized. The antagonist potencies of L-365,260 (CCK-B selective) and L-364,718 (CCK-A selective) against CCK-8 were also determined. Both CCK-8 and cerulein, when added to the serosal side of the tissue, evoked increases in the short-circuit current, having EC50 values of 0.8 and 0.2 nmol/L, respectively. Desulfated (SO3) CCK-8, CCK-4, gastrin17-I, pentagastrin, gastrin17-II, and gastrin13-I were relatively weak agonists (EC50 greater than 1000 nmol/L. Cholecystokinin octapeptide-induced short-current responses were competitively antagonized by L-364,718 (pA2, 10.3) and L-365,260 (pA2, 7.4). The high selectivity of the tissue for sulfated CCK-8 suggests that the secretory effect of CCK-8 on guinea pig ileal electrolyte transport is mediated by a CCK-A receptor. The potent effect of L-364,718 against CCK-8 is also consistent with an action at the A-subtype receptor.     

Effect of dietary cholesterol and indomethacin on cholelithiasis and gallbladder motility in guinea pig

This study examines the effects of dietary cholesterol and subcutaneous indomethacin on gallstone formation, gallbladder motility, and bile composition in guinea pigs. Guinea pigs on cholesterol diets developed gallstones which were not primarily composed of cholesterol and were not prevented by indomethacin. Animals receiving cholesterol diets showed significant gallbladder enlargement which was inhibited by indomethacin. Cholesterol did not alter gallbladder pressure-volume relationships or the response to CCK, while indomethacin diminished gallbladder tone. Although cholesterol feeding did not appear to alter smooth muscle contractility in the guinea pig gallbladder, it caused significant gallbladder enlargement by a mechanism which may be dependent on prostaglandins.This study was supported by National Institutes of Health grant AM 15304.     

The effect of proglumide on gallstone formation in guinea pigs

In this study, the chronic effects of proglumide (PGM, a cholecystokinin/gastrin receptor antagonist) on gallstone formation and hepatic bile secretion were investigated as follows: Group 1: Fed with low protein (14%) lithogenic diet. Group 2: Fed with the same lithogenic diet and was given PGM (250 mg/kg, bid, p. o.). Group 3: Fed with commercial guinea pig chow (protein content 22%). Eight weeks later the animals were operated under urethane anesthesia, the gallbladders were removed and examined for gallstones. Meanwhile, by bile duct cannulation, the hepatic bile flow and bile contents were measured. It was found that: (1) the animal model was valid for the purpose specified; (2) the rate of gallstone formation was significantly lower in PGM group than in the controls (17.5% vs 56.8%, P less than 0.01); and (3) PGM significantly enhanced the flow rates and electrolyte contents and decreased the unconjugated bilirubin content of the hepatic bile. It is concluded that PGM may suppress gallstone formation in guinea pigs on lithogenic diet, and this may be related to its stimulatory effect on hepatic bile secretion and to its ability to induce a decrease in unconjugated bilirubin in the hepatic bile.     

胆道梗阻对胆囊动力及Cajal间质细胞形态的影响

目的 探讨胆道梗阻诱发急性非结石性胆囊炎(AAC)对胆囊Cajal间质细胞超微结构的影响,并初步探究胆囊平滑肌收缩障碍的可能机制.方法 健康成年豚鼠60只,胆总管结扎(BDL)方法构建豚鼠AAC模型.平均分为5组,即假手术对照组(Sham)、BDLl2h(BDL-12)、24h (BDL-24)、48h(BDL-48)以及72h(BDL-72)组.到实验时间后收集胆囊标本,HE染色后光学显微镜观察各组胆囊病理改变.每只胆囊取3条肌条(8 mm×3 mm),固定于恒温浴槽,分别给予不同浓度的八肽胆囊收缩素(CCK-8,1010 mmol/L、109 mmol/L、10-8 mmol/L、107 mmol/L和10-6mmol/L)、乙酰胆碱(Ach,108 mmol/L、107 mmol/L、106 mmol/L、105 mmol/L和10-4 mmol/L)以及KCI(60 mmmol/L),利用张力换能器记录胆囊平滑肌肌条的收缩活动.采用透射电镜检测Sham 组、BDL-12组和BDL-72组豚鼠胆囊Cajal问质细胞的形态学改变.结果 Sham组和BDL-12组未见明显炎性反应;与Sham组相比,BDL-48组及BDL-72组胆囊组织病理学评分差异有统计学意义(P＜0.05).加入CCK-8、Ach和KCI后,各组胆囊平滑肌收缩振幅均增加,且呈浓度依赖性;与Sham组相比,各组效应值均有下降,有统计学意义(P＜0.05).与Sham组相比,BDL-12组胆囊Cajal间质细胞形态发生改变,BDL-72组改变更为明显.结论 胆道梗阻可以诱发AAC.在AAC 早期胆囊炎症尚未发生时便可能有胆囊平滑肌的收缩障碍存在,而胆囊Cajal间质细胞可能是收缩障碍的一个重要中间环节.

Abstract：

Objective To explore the effect of biliary obstruction caused acute acalculous cholecystitis (AAC) on ultrastructure of gallbladder interstitial cells of Cajal (ICCs),and the possible mechanism of impaired contraction of gallbladder smooth muscle. Methods Total 60 healthy adult guinea pigs were in this study. The guinea pigs AAC model was induced by common bile duct ligation (BDL). The guinea pigs were divided into five groups equally,including sham control group (Sham),BDL for 12 hours (BDL-12),24 hours (BDL-24),48 hours (BDL-48) and 72 hours (BDL-72)groups. The gallbladder specimens were collected by the end of study. Gallbladder pathological changes were observed with HE staining under light microscope. Three muscle strips were collected of each gallbladder,fixed in constant temperature water bath with different concentration of eight peptide cholecystokinin agonist (CCK-8,1010 mmol/L,10-9 mmol/L,10-8 mmol/L,10-7 mmol/L and 10-6mmol/L),acetylcholine (Ach,10-8 mmol/L,107 mmol/L,10-6 mmol/L,10-5 mmol/L,10-4 mmol/L)and potassium chloride (KC1) (60 mmol/L). The contraction activity of gallbladder muscle strips was recorded by tonotransducer. The ultrastracture changes of gallbladder ICC in sham,BDL-12 and BDL-72 groups was examined by transmission electron microscopy. Results There was no obvious inflammation in Sham and BDL-12 groups. Compared with sham group,there were significant differences of biology score of gallbladder in BDL-48 and BDL-72 groups (P＜0. 05). After adding CCK-8,Ach and KC1,the contraction amplitude of gallbladder muscle increased in each group,and in dose-dependent manner. Compared with sham group,the effect value of each other groups decreased significantly (P＜0. 05). Compared with sham group,the morphology of ICC changed in BDL-12group,and more obvious in BDL-72 group. Conclusion Biliary obstruction can induce AAC. At the earlier stage of ACC,the impaired contraction of gallbladder smooth muscle present even without gallbladder inflammation occurrence. ICC may play an important role in impaired contraction.     

Replacement of cholesterol gallstones by murideoxycholyl taurine gallstones in prairie dogs fed murideoxycholic acid

The effect of two hydrophilic bile acids, murideoxycholic acid (3 alpha,6 beta-dihydroxy-5 beta-cholanoic acid) and ursodeoxycholic acid, on cholesterol and bile acid metabolism and hepatic pathology and gallstone composition was studied in the prairie dog. Cholesterol gallstones were induced by feeding a diet containing 1.2% cholesterol for 75 days. The animals were divided into six groups, and gallstone regression was studied as follows: groups 2 and 5, chow plus 0.2% cholesterol; groups 3 and 6, chow plus 0.2% cholesterol plus 0.15% ursodeoxycholic acid; groups 4 and 7, chow plus 0.2% cholesterol plus 0.15% murideoxycholic acid. Animals in groups 2 to 4 were killed after an additional 6 wk; animals in groups 5 to 7 were killed after an additional 12 wk. Gallstone dissolution did not occur in any group. The gallstones in groups 2, 3, 5 and 6 were typical cholesterol aggregates, as determined by polarized light microscopy and Fourier transform infrared spectrometry. The gallstones of the murideoxycholic acid group were large, solitary, dark stones that appeared radiopaque under 22 kVp x-ray examination. Scanning electron microscopy showed that in these stones the cholesterol crystals had been replaced by an amorphous material, both within the stone and on the stone surface. Chemical analysis indicated that at the end of 12 wk the calcium/sodium salt of the taurine conjugate of murideoxycholic acid (murideoxycholyl taurine) comprised 70% of the stones; protein, cholesterol and small amounts of other bile salts were also present. In vitro studies confirmed the insolubility of the sodium and calcium salts of murideoxycholyl taurine. These studies indicate that the hydrophilic bile acids, murideoxycholic acid and ursodeoxycholic acid, did not achieve gallstone dissolution under the conditions used. In the animals fed murideoxycholic acid, an insoluble calcium salt of murideoxycholyl taurine replaced cholesterol as the major constituent of gallbladder stones. This is the first example of an insoluble dihydroxy taurine-conjugated bile acid; administration of the unconjugated bile acid induced precipitation of a kind of gallstone not previously reported. The final result was transformation of cholesterol stones to bile salt stones.     

Age-associated gallstone formation in male and female CCK-1(A) receptor-deficient mice

Background Gallbladder dysmotility accelerates cholelithiasis. In turn, gallbladder dysmotility can occur secondary to inflammation and excess cholesterol accumulation in gallbladder smooth muscle. Methods The present study was designed to determine how much gallbladder dysmotility contributes to gallstone formation as a primary cause and whether a sex difference exists in gallstone formation by comparing cholecystokinin-1 receptor gene-deficient [CCK-1R(−/−)] male and female mice. Results No sludge or gallstone formation was observed in mice at 6 months of age. The frequency of sludge and gallstone formation in mice at 12 and 24 months of age was slightly higher in female CCK-1R(−/−) mice than in males, but the difference was not significant. Conclusions Gallbladder dysmotility may have accelerated sludge and gallstone formation, but its contribution was limited. A 12-month period was required to produce gallstones, and after the mice reached 12 months of age, further ageing did not increase the frequency of gallstones. The effect of sex did not reach a significant level.