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Hernández-Moreno D, Morales S, Camello-Almaraz C, Pozo MJ, Camello PJ. Monochloramine effects on gallbladder contractility. Clin Exp Pharmacol Physiol 2020; 48:597-604. [PMID: 33352621 DOI: 10.1111/1440-1681.13453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 12/04/2020] [Indexed: 11/28/2022]
Abstract
Digestive inflammatory processes induce motility alterations associated with an increase in reactive oxygen species production, including monochloramine (NH2 Cl). The aim of the study was to characterize the effects of the naturally occurring oxidant monochloramine in the guinea pig gallbladder. We used standard in vitro contractility technique to record guinea pig gallbladder strips contractions. NH2 Cl caused a concentration-dependent contraction which was reduced by inhibition of extracellular Ca2+ influx and tyrosine kinase pathways. The PKC antagonist GF109203X also reduced the response but not after previous tyrosine kinase inhibition, suggesting that PKC is activated by tyrosine kinase activity. The NH2 Cl contractile effect was also reduced by inhibitors of mitogen-activated protein kinase (MAPK), nitric oxide synthase, phospholipase A2 and cyclooxygenase. In addition, NH2 Cl impaired the responses to CCK, tissue depolarization and electrical field stimulation. In conclusion, we present new evidence that monochloramine impairs not only the gallbladder response to CCK but also to membrane depolarization and nervous plexus stimulation, and that tyrosine kinase, PKC, MAPK and NO pathways are involved in the contractile direct effect of monochloramine.
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Affiliation(s)
- David Hernández-Moreno
- Department of Environment and Agronomy, National Institute for Agricultural and Food Research and Technology (INIA), Madrid, Spain
| | - Sara Morales
- Department of Physiology, School of Nursing and Occupational Therapy, Institute of Biomarkers of Metabolic Pathologies, University of Extremadura, Caceres, Spain
| | - Cristina Camello-Almaraz
- Department of Physiology, School of Nursing and Occupational Therapy, Institute of Biomarkers of Metabolic Pathologies, University of Extremadura, Caceres, Spain
| | - María J Pozo
- Department of Physiology, School of Nursing and Occupational Therapy, Institute of Biomarkers of Metabolic Pathologies, University of Extremadura, Caceres, Spain
| | - Pedro J Camello
- Department of Physiology, School of Nursing and Occupational Therapy, Institute of Biomarkers of Metabolic Pathologies, University of Extremadura, Caceres, Spain
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Plasma Procalcitonin Is Useful for Predicting the Severity of Acute Cholecystitis. Emerg Med Int 2020; 2020:8329310. [PMID: 32399305 PMCID: PMC7201449 DOI: 10.1155/2020/8329310] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 12/16/2019] [Accepted: 12/26/2019] [Indexed: 12/24/2022] Open
Abstract
Background Acute cholecystitis is a common complication of cholelithiasis. Delayed diagnosis may constitute morbidity and mortality; therefore, early diagnosis and determining the severity of acute cholecystitis are crucial. Objectives This study aimed to determine the validity of blood procalcitonin (PCT) levels in assessing the severity of acute cholecystitis. Methods The Emergency Department (ED) patients diagnosed as acute cholecystitis were included in the study. Patients were allocated into three severity grades according to the Tokyo Guidelines 2013. PCT level was measured after the clinical and radiological diagnosis of acute cholecystitis in the ED. Results Ninety-five patients diagnosed with acute cholecystitis, among them 48 of were male. Forty patients (42.1%) were allocated to grade 1, 19 (20%) to grade 2, and 36 (37.9%) to grade 3. The median values of PCT were 0.104 ng/ml, 0.353 ng/ml, and 1.466 ng/ml for grade 1, 2, and 3 patients, respectively (p < 0.001). Conclusion Blood procalcitonin levels can be used to determine the severity of acute cholecystitis effectively.
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Zhang L, Pan C, Yang B, Xiao Y, Yu B. Enhanced expression of cystathionine β-synthase and cystathionine γ-lyase during acute cholecystitis-induced gallbladder inflammation. PLoS One 2013; 8:e82711. [PMID: 24349344 PMCID: PMC3857271 DOI: 10.1371/journal.pone.0082711] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Accepted: 10/28/2013] [Indexed: 12/20/2022] Open
Abstract
Background Hydrogen sulfide (H2S) has recently been shown to play an important role in the digestive system, but the role of endogenous H2S produced locally in the gallbladder is unknown. The aim of this study was to investigate whether gallbladder possesses the enzymatic machinery to synthesize H2S, and whether H2S synthesis is changed in gallbladder inflammation during acute acalculous cholecystitis (AC). Methods Adult male guinea pigs underwent either a sham operation or common bile duct ligation (CBDL). One, two, or three days after CBDL, the animals were sacrificed separately. Hematoxylin and eosin-stained slides of gallbladder samples were scored for inflammation. H2S production rate in gallbladder tissue from each group was determined; immunohistochemistry and western blotting were used to determine expression levels of the H2S-producing enzymes cystathionine β-synthase (CBS) and cystathionine γ-lyase (CSE) in gallbladder. Results There was a progressive inflammatory response after CBDL. Immunohistochemistry analysis showed that CBS and CSE were expressed in the gallbladder epithelium, muscular layer, and blood vessels and that the expression increased progressively with increasing inflammation following CBDL. The expression of CBS protein as well as the H2S-production rate was significantly increased in the animals that underwent CBDL, compared to those that underwent the sham operation. Conclusions Both CBS and CSE are expressed in gallbladder tissues. The expression of these enzymes, as well as H2S synthesis, was up-regulated in the context of inflammation during AC.
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Affiliation(s)
- Li Zhang
- Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Chenwei Pan
- Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan, China
- Department of Infectious Disease, the Second Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Bin Yang
- Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Yong Xiao
- Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Baoping Yu
- Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan, China
- * E-mail:
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Lavoie B, Nausch B, Zane E, Leonard M, Balemba O, Bartoo A, Wilcox R, Nelson M, Carey M, Mawe G. Disruption of gallbladder smooth muscle function is an early feature in the development of cholesterol gallstone disease. Neurogastroenterol Motil 2012; 24:e313-24. [PMID: 22621672 PMCID: PMC3378777 DOI: 10.1111/j.1365-2982.2012.01935.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
UNLABELLED BACKGROUND; Decreased gallbladder smooth muscle (GBSM) contractility is a hallmark of cholesterol gallstone disease, but the interrelationship between lithogenicity, biliary stasis, and inflammation are poorly understood. We studied a mouse model of gallstone disease to evaluate the development of GBSM dysfunction relative to changes in bile composition and the onset of sterile cholecystitis. METHODS BALB/cJ mice were fed a lithogenic diet for up to 8 weeks, and tension generated by gallbladder muscle strips was measured. Smooth muscle Ca(2+) transients were imaged in intact gallbladder. KEY RESULTS Lipid composition of bile was altered lithogenically as early as 1 week, with increased hydrophobicity and cholesterol saturation indexes; however, inflammation was not detectable until the fourth week. Agonist-induced contractility was reduced from weeks 2 through 8. GBSM normally exhibits rhythmic synchronized Ca(2+) flashes, and their frequency is increased by carbachol (3 μm). After 1 week, lithogenic diet-fed mice exhibited disrupted Ca(2+) flash activity, manifesting as clustered flashes, asynchronous flashes, or prolonged quiescent periods. These changes could lead to a depletion of intracellular Ca(2+) stores, which are required for agonist-induced contraction, and diminished basal tone of the organ. Responsiveness of Ca(2+) transients to carbachol was reduced in mice on the lithogenic diet, particularly after 4-8 weeks, concomitant with appearance of mucosal inflammatory changes. CONCLUSIONS & INFERENCES These observations demonstrate that GBSM dysfunction is an early event in the progression of cholesterol gallstone disease and that it precedes mucosal inflammation.
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Affiliation(s)
- B. Lavoie
- Department of Anatomy and Neurobiology, University of Vermont School of Medicine, Burlington, VT
| | - B. Nausch
- Department of Anatomy and Neurobiology, University of Vermont School of Medicine, Burlington, VT
| | - E.A. Zane
- Department of Medicine, Harvard Medical School, Gastroenterology Division, Brigham and Women's Hospital, Boston, MA
| | - M.R. Leonard
- Department of Medicine, Harvard Medical School, Gastroenterology Division, Brigham and Women's Hospital, Boston, MA
| | - O.B. Balemba
- Department of Anatomy and Neurobiology, University of Vermont School of Medicine, Burlington, VT
| | - A.C. Bartoo
- Department of Anatomy and Neurobiology, University of Vermont School of Medicine, Burlington, VT
| | - R. Wilcox
- Department of Pathology, University of Vermont School of Medicine, Burlington, VT
| | - M.T. Nelson
- Department of Pharmacology, University of Vermont School of Medicine, Burlington, VT
| | - M.C. Carey
- Department of Medicine, Harvard Medical School, Gastroenterology Division, Brigham and Women's Hospital, Boston, MA
| | - G.M. Mawe
- Department of Anatomy and Neurobiology, University of Vermont School of Medicine, Burlington, VT
- Department of Pharmacology, University of Vermont School of Medicine, Burlington, VT
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Colli A, Conte D, Valle SD, Sciola V, Fraquelli M. Meta-analysis: nonsteroidal anti-inflammatory drugs in biliary colic. Aliment Pharmacol Ther 2012; 35:1370-8. [PMID: 22540869 DOI: 10.1111/j.1365-2036.2012.05115.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2012] [Revised: 01/30/2012] [Accepted: 04/09/2012] [Indexed: 12/17/2022]
Abstract
BACKGROUND Biliary colic is a common manifestation of cholelithiasis, developing in about one-third of patients. Even if nonsteroid anti-inflammatory drugs (NSAIDs) have widely been used to relieve biliary pain, there is a lack of systematic review of treatments on this issue. AIM To assess the potential benefits in terms of both pain control and reduction of complications, and the potential harms of NSAIDs in patients with biliary colic. METHODS Data from randomised clinical trials (RCTs) comparing NSAIDs with no treatment, placebo or other drugs in patients with biliary colic, were collected from Medline and Embase. The outcome measures were expressed as odds ratio and relative risk and then pooled using fixed or random-effect models. RESULTS Eleven RCTs involving 1076 subjects (268 men, 808 women; 18-86 years), including 442 controls were analysed. In comparison with placebo, NSAIDs led to a significantly higher proportion of patients with complete pain relief (RR 3.77, 95%CI 1.65-8.61; I(2) : 73%) and a significantly lower rate of complications (RR 0.53, 95% CI 0.31-0.89; I(2) : 35%). In comparison with other drugs, NSAIDs were more efficacious in controlling pain than spasmolytics (RR 1.47, 95% CI 1.03-2.10; I(2) : 55%); there was no difference between NSAIDs and opioids (RR 1.05, 95% CI 0.82-1.33; I(2) : 74%). CONCLUSIONS In patients with biliary colic NSAIDs are the first-choice treatments as they control pain with the same efficacy of opioids and significantly reduce the proportion of patients with severe complications. However, the lack of high-quality RCTs and the presence of consistent heterogeneity among studies may partially flaw these results.
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Affiliation(s)
- A Colli
- Department of Internal Medicine, Ospedale "A. Manzoni", Lecco, Italy
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Tempol protects the gallbladder against ischemia/reperfusion. J Physiol Biochem 2010; 66:161-72. [DOI: 10.1007/s13105-010-0021-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2010] [Accepted: 05/04/2010] [Indexed: 12/29/2022]
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Soylu S, Aydin C, Bagcivan I, Yildirim S, Koyuncu A, Topcu O, Arici S. Effects of NO/L-arginine pathway on gallbladder contractility in bile duct ligated guinea pigs. J Surg Res 2008; 155:70-6. [PMID: 19394644 DOI: 10.1016/j.jss.2008.08.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2008] [Revised: 07/23/2008] [Accepted: 08/01/2008] [Indexed: 02/07/2023]
Abstract
BACKGROUND Common bile duct ligation (CBDL) produces gallbladder distension and acute inflammation similar to that seen in human acute acalculous cholecystitis. CBDL in the guinea pig affects smooth muscle contractility. The aim of this study was to determine whether the nitric oxide-L-arginine pathway plays a role in the inflammatory process and abnormal gallbladder contractility that occur after CBDL. MATERIALS AND METHODS Contractility of gallbladder muscle from CBDL and sham-operated guinea pigs was studied in vitro. Animals were treated with saline, aminoguanidine (AG), or an aminoguanidine + L-arginine combination (AG + L-Arg) in vivo. Potassium chloride, carbachol, and electric field stimulation (EFS) were used for contracting the gallbladder muscle strips or activating intrinsic nerves. Hematoxylin and eosin-stained slides of muscle strips were scored for inflammation. RESULTS Contraction responses to carbachol and EFS were decreased significantly in CBDL guinea pigs compared with those in the sham-operated group. AG partly reversed the smooth muscle contractile response to carbachol and EFS, but did not reduce the inflammation score. Treatment with AG + L-arg did not reverse either the contraction response or the inflammation score. CONCLUSIONS These findings suggest that AG and AG + L-Arg treatments have no beneficial effect on inflammation in guinea pigs after CBDL, although AG significantly reversed the effect on muscle contractility (P < 0.05). This improvement was independent of inflammation and may be due to a decreased level of NO and its diminished relaxant effect.
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Affiliation(s)
- Sinan Soylu
- Department of General Surgery, Cumhuriyet University School of Medicine, Sivas, Turkey
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Bartoo AC, Nelson MT, Mawe GM. ATP induces guinea pig gallbladder smooth muscle excitability via the P2Y4 receptor and COX-1 activity. Am J Physiol Gastrointest Liver Physiol 2008; 294:G1362-8. [PMID: 18436624 PMCID: PMC2921626 DOI: 10.1152/ajpgi.00043.2008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The purpose of this study was to elucidate the mechanisms by which ATP increases guinea pig gallbladder smooth muscle (GBSM) excitability. We evaluated changes in membrane potential and action potential (AP) frequency in GBSM by use of intracellular recording. Application of ATP (100 microM) caused membrane depolarization and a significant increase in AP frequency that were not sensitive to block by tetrodotoxin (0.5 microM). The nonselective P2 antagonist, suramin (100 microM), blocked the excitatory response, resulting in decreased AP frequency in the presence of ATP. The excitatory response to ATP was not altered by pyridoxal-phosphate-6-azophenyl-2,4-disulfonic acid (30 microM), a nonselective P2X antagonist. UTP also caused membrane depolarization and increased AP frequency, with a similar dose-response relationship as ATP. RT-PCR demonstrated that the P2Y(4), but not P2Y(2), receptor subtype is expressed in guinea pig gallbladder muscularis. ATP induced excitation was blocked by indomethacin (10 microM) and the cyclooxygenase (COX)-1 inhibitor SC-560 (300 nM), but not the COX-2 inhibitor nimesulide (500 nM). These data suggest that ATP stimulates P2Y(4) receptors within the gallbladder muscularis and, in turn, stimulate prostanoid production via COX-1 leading to increased excitability of GBSM.
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Affiliation(s)
- Aaron C. Bartoo
- Department of Anatomy and Neurobiology, University of Vermont College of Medicine, Burlington, Vermont
| | - Mark T. Nelson
- Department of Pharmacology, University of Vermont College of Medicine, Burlington, Vermont
| | - Gary M. Mawe
- Department of Anatomy and Neurobiology, University of Vermont College of Medicine, Burlington, Vermont,Department of Pharmacology, University of Vermont College of Medicine, Burlington, Vermont
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Portincasa P, Di Ciaula A, Wang HH, Palasciano G, van Erpecum KJ, Moschetta A, Wang DQH. Coordinate regulation of gallbladder motor function in the gut-liver axis. Hepatology 2008; 47:2112-26. [PMID: 18506897 DOI: 10.1002/hep.22204] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Gallstones are one of the most common digestive diseases with an estimated prevalence of 10%-15% in adults living in the western world, where cholesterol-enriched gallstones represent 75%-80% of all gallstones. In cholesterol gallstone disease, the gallbladder becomes the target organ of a complex metabolic disease. Indeed, a fine coordinated hepatobiliary and gastrointestinal function, including gallbladder motility in the fasting and postprandial state, is of crucial importance to prevent crystallization and precipitation of excess cholesterol in gallbladder bile. Also, gallbladder itself plays a physiopathological role in biliary lipid absorption. Here, we present a comprehensive view on the regulation of gallbladder motor function by focusing on recent discoveries in animal and human studies, and we discuss the role of the gallbladder in the pathogenesis of gallstone formation.
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Affiliation(s)
- Piero Portincasa
- Department of Internal Medicine and Public Medicine, Clinica Medica A. Murri, University of Bari Medical School, Bari, Italy.
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Myers SI, Bartula LL, Colvin MP, Parkman HP. Cholecystokinin (CCK) down regulates PGE2 and PGI2 release in inflamed Guinea pig gallbladder smooth muscle cell cultures. Prostaglandins Leukot Essent Fatty Acids 2005; 73:121-6. [PMID: 16023335 DOI: 10.1016/j.plefa.2005.04.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2005] [Accepted: 04/09/2005] [Indexed: 10/25/2022]
Abstract
This study examines the hypothesis that cholecystitis down-regulates Guinea pig gallbladder (GPGB) smooth muscle cholecystokinin (CCK)-stimulated prostaglandin (PG) release. Guinea pig gallbladder from Control and 48 h bile duct ligated (BDL) animals were placed in cell culture and grown to confluence. The cultures underwent Western Blot analysis for smooth muscle cell content of COX-1, COX-2, Prostacyclin Synthase (PS), or were incubated with CCK at 10(-8)M or 10(-6)M with and without indomethacin for 1h and analyzed for release of 6-keto-PGF1alpha, PGE2 and TxB2 by EIA. BDL increased Guinea pig gallbladder cell culture basal PGE2 and PGI2 release which was in part due to increased COX-2 content. CCK incubation down-regulated BDL Guinea pig gallbladder cell culture release of 6-keto-PGF1alpha and PGE2 and down-regulated COX-2 content but did not alter the Control group. The decrease in CCK-mediated BDL cell Guinea pig gallbladder release may be an endogenous mechanism to limit physiologic derangements induced by increased endogenous gallbladder PG synthesis during early acute cholecystitis.
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Affiliation(s)
- Stuart I Myers
- Department of Surgery, Virginia Commonwealth University, Richmond, VA, USA.
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Portincasa P, Di Ciaula A, vanBerge-Henegouwen GP. Smooth muscle function and dysfunction in gallbladder disease. Curr Gastroenterol Rep 2004; 6:151-62. [PMID: 15191695 DOI: 10.1007/s11894-004-0043-0] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The gallbladder epithelium and smooth muscle layer are exposed to concentrated biliary solutes, including cholesterol and potentially toxic hydrophobic bile salts, which are able to influence muscle contraction. Physiologically, gallbladder tone is regulated by spontaneous muscle activity, hormones, and neurotransmitters released into the muscle from intrinsic neurons and extrinsic sympathetic nerves. Methods to explore gallbladder smooth muscle function in vitro include cholecystokinin (CCK) receptor-binding studies and contractility studies. In human and animal models, studies have focused on cellular and molecular events in health and disease, and in vitro findings mirror in vivo events. The interplay between contraction and relaxation of the gallbladder muscularis leads in vivo to appropriate gallbladder emptying and refilling during fasting and postprandially. Defective smooth muscle contractility and/or relaxation are found in cholesterol stone-containing gallbladders, featuring a type of gallbladder leiomyopathy; defects of CCKA receptors and signal transduction may coexist with abnormal responses to oxidative stress and inflammatory mediators. Abnormal smooth musculature contractility, impaired gallbladder motility, and increased stasis are key factors in the pathogenesis of cholesterol gallstones.
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Affiliation(s)
- Piero Portincasa
- Gastrointestinal Research Unit, University of Medical Center Utrecht, The Netherlands.
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Alcón S, Morales S, Camello PJ, Pozo MJ. Contribution of different phospholipases and arachidonic acid metabolites in the response of gallbladder smooth muscle to cholecystokinin. Biochem Pharmacol 2002; 64:1157-67. [PMID: 12234620 DOI: 10.1016/s0006-2952(02)01259-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Guinea pig gallbladder muscle strips were used to investigate the contribution of different sources of diacylglicerol (DAG) in the cholecystokinin (CCK)-induced contraction. The involvement of arachidonic acid (AA) in this response was also investigated. Three distinct pathways for DAG production were investigated with specific phospholipase (PL) inhibitors. U-73122 (10 microM) was used for inhibition of phosphoinositide-specific-PLC (PI-PLC), D-609 (100 microM) for phosphatidylcholine specific-PLC (PC-PLC), and propranolol (100 microM) for phospholipase D (PLD). Separate or combined inhibition of each of these enzymes showed that the CCK-induced output of DAG involves the parallel activation of each of these phospholipases. Thus, after inhibition of a PL subtype, the remaining subtypes were able to functionally compensate in mediating CCK-induced contraction. Inhibition of AA production via DAG-lipase or phospholipase A(2) (PLA(2)) was accomplished using RHC-80267 (40 microM), mepacrine (100 microM) and 4-BPB (100 microM). These inhibitors diminished contractile response, indicating that AA is an important modulator of CCK-induced contraction. Indomethacin (10 microM) and nordihydroguaiaretic acid (NDGA, 100 microM), which inhibit subsequent steps in AA metabolism through the cyclooxygenase and 5-lipooxygenase pathways, also inhibited contractions. Taken together, these results show that CCK redundantly activates PC-PLC, PI-PLC and PLD, to produce DAG, which in turn stimulates PKC and provides a substrate for the generation of AA. sPLA(2) is also a source of AA, whose metabolites are, in part, responsible for determining the magnitude of the CCK-evoked contraction.
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Affiliation(s)
- Soledad Alcón
- Department of Physiology, University of Extremadura, 10071 Cáceres, Spain
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O'Riordan AM, Quinn T, Baird AW. Role of prostaglandin E(2) and Ca(2+) in bradykinin induced contractions of guinea-pig gallbladder in vitro. Eur J Pharmacol 2001; 431:245-52. [PMID: 11728432 DOI: 10.1016/s0014-2999(01)01426-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In this study, we investigated the contribution of prostaglandin E(2) to bradykinin induced contractions of guinea-pig gallbladder in vitro and characterized the sources of activator Ca(2+) for the bradykinin mediated contractions. Contractions induced by bradykinin in guinea-pig gallbladder smooth muscle strips were significantly attenuated by the cyclooxygenase inhibitor piroxicam (10 microM). In the presence of piroxicam, a threshold concentration of prostaglandin E(2) (1 nM) significantly enhanced the contractile response to subsequent challenge with bradykinin. Contractile responses to bradykinin were abolished in a Ca(2+)-free medium plus EDTA. The inhibitor of receptor mediated Ca(2+) entry, SK&F 96365 (1-[beta-[3-(4-methoxyphenyl)-propoxy]-4-methoxyphenethyl]-1H-imidazole hydrochloride, 10-50 microM) dose dependently abolished the response to bradykinin, while this response was only partially attenuated by nifedipine (10-50 microM; a voltage-operated Ca(2+) channel antagonist). Thapsigargin (an inhibitor of the sarcoplasmic reticulum calcium ATP-ase pump, 1 microM) produced sustained contractions of guinea-pig gallbladder strips that were dependent on extracellular Ca(2+). After incubation of strips in a Ca(2+)-free medium with thapsigargin, replacement of Ca(2+) caused a large sustained contraction. We conclude that the contractile response of guinea-pig gallbladder to bradykinin is modulated by prostaglandin E(2). Bradykinin induced contractions of guinea-pig gallbladder are highly dependent on extracellular Ca(2+) which enters through store-operated Ca(2+) channels and partially through voltage-operated Ca(2+) channels.
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Affiliation(s)
- A M O'Riordan
- Department of Veterinary Physiology and Biochemistry, Faculty of Veterinary Medicine, University College Dublin, Shelbourne Road, Dublin 4, Ireland
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