6-ketoprostaglandin-f1-alpha and Cholecystitis

Acute cholecystitis is associated with increased gallbladder prostanoid formation and the inflammatory changes and prostanoid increases can be inhibited by nonsteroidal anti-inflammatory agents. Recent information indicates that prostanoids are produced by two cyclooxygenase (COX) enzymes, COX-1 and COX-2. The purpose of this study was to determine the COX enzymatic pathway in gallbladder mucosal cells involved in the production of prostanoids stimulated by inflammatory agents. Human gallbladder mucosal cells were isolated from cholecystectomy specimens and maintained in cell culture and studied in comparison with cells from a well differentiated gallbladder mucosal carcinoma cell line. COX enzymes were evaluated by Western immunoblotting and prostanoids were measured by ELISA. Unstimulated and stimulated cells were exposed to specific COX-1 and COX-2 inhibitors. In both normal and transformed cells constitutive COX-1 was evident and in gallbladder cancer cells lysophosphatidyl choline (LPC) induced the formation of constitutive COX-1 enzyme. While not detected in unstimulated normal mucosal cells and cancer cells, COX-2 protein was induced by both lipopolysaccharide (LPS) and LPC. Unstimulated gallbladder mucosal cells and cancer cells produced prostaglandin E2 (PGE2) and prostacyclin (6-keto prostaglandin F1alpha, 6-keto PGF1alpha) continuously. In freshly isolated normal gallbladder mucosal cells, continuously produced 6 keto PGF1alpha was inhibited by both COX-1 and COX-2 inhibitors while PGE2 levels were not affected. Both LPS and LPC stimulated PGE2 and 6 keto PGF1alpha formation were blocked by COX-2 inhibitors in freshly isolated, normal human gallbladder mucosal cells and in the gallbladder cancer cells. The prostanoid response of gallbladder cells stimulated by proinflammatory agents is inhibited by COX-2 inhibitors suggesting that these agents may be effective in treating the pain and inflammation of gallbladder disease.

Topics: 6-Ketoprostaglandin F1 alpha; Blotting, Western; Cholecystitis; Cyclooxygenase 1; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Cyclooxygenase Inhibitors; Dinoprostone; Female; Gallbladder; Gallbladder Neoplasms; Humans; Isoenzymes; Lipopolysaccharides; Lysophosphatidylcholines; Male; Membrane Proteins; Middle Aged; Mucous Membrane; Nitrobenzenes; Prostaglandin-Endoperoxide Synthases; Prostaglandins; Pyrazoles; Sulfonamides; Tumor Cells, Cultured

This study examines the hypothesis that PAF stimulates release of PGI2 from inflamed rabbit gallbladder explant cell cultures. New Zealand white rabbits underwent bile duct ligation for 72 h (72 h BDL), or sham operation, Sham and 72 h BDL gallbladder explants were placed in culture, and the cells grown to 75% confluence. The cells were exposed to increasing concentrations of PAF for 60 min. The media analyzed for eicosanoid release by EIA and the cells analyzed for cyclooxygenase and prostacyclin synthase content by immunoblot analysis. PAF increased release of 6-keto-PGF1 alpha from the 72 h BDL gallbladder cell cultures in a dose-related manner which was inhibited by indomethacin preincubation by 90%. The increased 72 h BDL cell release of 6-keto-PGF1 alpha was not associated with changes in the content of cyclooxygenase or prostacyclin synthase. PAF did not alter eicosanoid release from sham control cell cultures. These data suggest that PAF can only up-regulate endogenous 6-keto-PGF1 alpha release from the 72 h BDL cells that had been previously stimulated by inflammation. PAF may thus contribute to gallbladder distention and injury by chronic stimulation of inflamed gallbladder PGI2 release.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Antibodies; Cells, Cultured; Cholecystitis; Cytochrome P-450 Enzyme System; Dinoprost; Dose-Response Relationship, Drug; Epoprostenol; Gallbladder; Immunoblotting; Indomethacin; Intramolecular Oxidoreductases; Isomerases; Platelet Activating Factor; Prostaglandin-Endoperoxide Synthases; Proteins; Rabbits; Thromboxane B2

Gallbladder cell cultures obtained from rabbits subjected to sham or 72 h of bile duct ligation (72 h BDL, cholecystitis model) were incubated with calcium ionophore (A23187), dibutyryl cAMP (cAMP), and phorbol 12,13-diacetate (phorbol) to determine the intracellular signal transduction mechanisms responsible for increased inflamed gallbladder eicosanoid synthesis. Incubation of sham and 72 h BDL cell cultures with A23187 or phorbol significantly increased, whereas cAMP decreased, release of 6-keto-PGF1 alpha, PGE2, thromboxane B2 (measured by enzyme immunoassay) in a dose-related manner. Seventy-two-hour BDL cell cultures contained a specific 2-fold increased level of prostacyclin synthase compared to sham cell cultures which was not altered by preincubation with A23187, phorbol or cAMP. These findings suggest that increased PGI2 release in the sham and inflamed cell cultures following A23187 and phorbol stimulation was mediated in part via the inositol triphosphate pathway and protein kinase C activation and was not associated with altered cyclooxygenase or prostacyclin synthase content.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Bucladesine; Calcimycin; Cells, Cultured; Cholecystitis; Cytochrome P-450 Enzyme System; Dinoprostone; Eicosanoids; Enzyme Activation; Epoprostenol; Fibroblasts; Gallbladder; Intramolecular Oxidoreductases; Ionophores; Isomerases; Male; Phorbol Esters; Prostaglandin-Endoperoxide Synthases; Protein Kinase C; Rabbits; Signal Transduction; Thromboxane B2

The stimulus for increased gallbladder eicosanoid synthesis during cholecystitis is unknown. This study examines the hypothesis that increased intragallbladder pressure stimulates endogenous gallbladder eicosanoid release. Rabbit gallbladders were perfused in vitro at 1 ml/minute with oxygenated Krebs-Henseleit buffer and subjected to 0, 12 or 24 mm Hg of intraluminal gallbladder pressure. Release of 6-keto-PGF1 alpha infinity PGE2 and thromboxane B2 were measured in all groups after 15 and 30 and 60 minutes of perfusion by enzyme immunoassay and gallbladders were examined histologically. Increasing intraluminal gallbladder pressure concomitantly increased gallbladder 6-keto-PGF1 alpha release 2 fold or more at all time of perfusion and altered gallbladder mucosal architecture by increasing basolateral edema in the submucosal space. Infusion of indomethacin (10 micrograms/ml in the perfusion media) decreased 6-keto-PGF1 alpha release from the in vitro perfused gallbladders subjected to 24 mm Hg by 70%. Increased gallbladder eicosanoid release during early cholecystitis may in part be related to the physical force of increased gallbladder intraluminal pressure on the gallbladder mucosa.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Cholecystitis; Dinoprostone; Gallbladder; Hydrostatic Pressure; Immunoenzyme Techniques; Indomethacin; Male; Perfusion; Rabbits; Thromboxane B2

Gallbladder explants from control rabbits and rabbits subjected to bile duct ligation (BDL) for 24 and 72 h (cholecystitis model) were placed in cell culture to determine the source for increased gallbladder prostanoid synthesis during cholecystitis. Cultures from control and 24 h BDL gallbladders grew spindle shaped fibroblasts which did not exhibit increased prostanoid synthesis. 72 h BDL gallbladder cell cultures grew large polygonal shaped cells which appeared to be 'stimulated fibroblasts' by light and electron microscopy and were associated with increased basal and bradykinin stimulated 6-keto-PGF1 alpha release and increased content of prostacyclin synthase when measured by enzyme immunoassay and protein immunoblot analysis respectively. Use of bradykinin antagonists showed that the bradykinin BK2 subtype receptor was the most prominent in the 72 h BDL cell cultures. The 'stimulated fibroblasts' were the source of bradykinin stimulated gallbladder 6-keto-PGF1 alpha synthesis in the inflamed rabbit gallbladder which was mediated by the bradykinin B2 subtype receptor.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Bile Ducts; Bradykinin; Cells, Cultured; Cholecystitis; Cytochrome P-450 Enzyme System; Dinoprostone; Fibroblasts; Gallbladder; Intramolecular Oxidoreductases; Isomerases; Ligation; Male; Prostaglandin-Endoperoxide Synthases; Prostaglandins; Rabbits; Receptors, Bradykinin; Thromboxane B2

Microsomal prostanoid synthesis was compared in normal gallbladders removed during organ donation and inflamed gallbladders removed at cholecystectomy. Normal human gallbladder microsomes demonstrated low rates of conversion of [14C]arachidonic acid to total labeled prostanoids, which increased during 1 to 30 min of incubation. Normal human gallbladder microsomes converted labeled substrate to all primary prostaglandins without demonstration of a major product. Inflamed human gallbladder microsomes increased the rate of conversion of [14C]arachidonic acid to total labeled prostanoids two or three times over the levels demonstrated by normal gallbladder microsomes at all times of incubation (p < 0.01). The main prostanoids synthesized by the inflamed human gallbladder microsomes were prostaglandin E2 and 6-keto-prostaglandin F1 alpha, which were increased four times over the levels demonstrated by normal gallbladder microsomes (p < 0.01). These data showed that inflammation of the human gallbladder was associated with increased synthesis of gallbladder 6-keto-prostaglandin F1 alpha and prostaglandin E2.

Topics: 6-Ketoprostaglandin F1 alpha; Arachidonic Acid; Cholecystitis; Dinoprostone; Epoprostenol; Gallbladder; Humans; Indomethacin; Intracellular Membranes; Microsomes

The profiling of eicosanoids, including prostaglandin E2 (PGE2), prostaglandin F2 alpha (PGF2 alpha), 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha), thromboxane B2 (TXB2) and leukotriene B4 (LTB4), in dog and human gall bladders was carried out by a combination of an effective and convenient clean-up procedure and gas chromatography with selected-ion monitoring. The clean-up procedure was based on the stepwise elution of their methyl ester derivatives from a silica gel column with n-hexane-ethyl acetate and ethyl acetate-methanol in various ratios. The LTB4 methyl ester was eluted with an n-hexane-ethyl acetate (2:1, v/v) fraction because LTB4 is more lipophilic than the other eicosanoids. The present method permitted the quantitation of trace amounts of eicosanoids, including LTB4, present in tissues in the order of pg/mg of protein, without interference from other endogenous substances. In experimental acalculous cholecystitis produced in dog, the levels of eicosanoids (except LTB4) were significantly changed. Of these eicosanoids, the level of 6-keto-PGF1 alpha was significantly higher in the seromuscular layer and correlated with the observed severe morphological changes. In human chronic cholecystitis with gallstones, the level of 6-keto-PGF1 alpha in the mucosal layer was significantly higher than that in the seromuscular layer. These data suggest that prostaglandin I2 may play an important pathophysiological role in the course of cholecystitis.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Cholecystitis; Dinoprost; Dinoprostone; Dogs; Eicosanoids; Female; Gallbladder; Gas Chromatography-Mass Spectrometry; Humans; Leukotriene B4; Male

Gallbladder tissue from patients with acute acalculous cholecystitis contains increased amounts of prostanoids when compared to normal gallbladder tissue. Platelet-activating factor (PAF) is a potent stimulus of eicosanoid formation. It has been implicated as a mediator of acute inflammatory processes and systemic responses to shock. In this study the role of PAF in acute acalculous cholecystitis was evaluated. Anesthetized cats underwent gallbladder perfusion with a physiologic buffer solution containing [14C]polyethylene glycol as a nonabsorbable tracer to quantitate mucosal water absorption. Platelet-activating factor was infused into the hepatic artery for 2 hours. Control experiments were performed when vehicle alone was infused. Experiments also were performed when indomethacin was administered intravenously and when indomethacin and PAF were administered. Gallbladder mucosal absorption/secretion and perfusate and tissue prostaglandin E (PGE) and 6 keto prostaglandin F1 alpha (6-keto PGF1 alpha) levels were evaluated. Gallbladder inflammation was evaluated by beta-glucuronidase and myeloperoxidase tissue concentrations and by a histologic scoring system. Platelet-activating factor eliminated gallbladder absorption and produced net fluid secretion associated with dose-related increases in perfusate PGE concentrations and gallbladder tissue PGE and 6 keto PGF1 alpha levels when compared to control values. Platelet-activating factor produced significant inflammation in the gallbladder with increases in the histologic score of inflammation and tissue lysosomal enzyme activities. Indomethacin significantly decreased the fluid secretion, prostanoid levels, and inflammation produced by PAF. The results suggest that PAF may induce acute gallbladder inflammation associated with systemic stress through a prostanoid-mediated mechanism.

Topics: 6-Ketoprostaglandin F1 alpha; Absorption; Acute Disease; Animals; Body Water; Cats; Cholecystitis; Gallbladder; Hemodynamics; Indomethacin; Peroxidase; Platelet Activating Factor; Prostaglandins; Prostaglandins E

Gallbladder prostanoid (PG) synthesis and histologic inflammatory changes were compared after 6, 24, and 72 hours of bile duct ligation (BDL) or cystic duct ligation (CDL) in the male rabbit. At each time interval the gallbladder was scored for degree of acute inflammation, examined by radiochromatography for endogenous PG synthesis and analyzed by ANOVA. BDL induced progressive increases in acute inflammation whereas prostanoid synthesis significantly increased only after the 6 and 72 hour groups. Indomethacin treatment inhibited PG synthesis in all BDL groups but only decreased the inflammation score in the 6 and 24 hour BDL groups. CDL did not induce progressive gallbladder inflammatory changes or prostanoid synthesis. These data show that prostanoids are intimately involved with the development of early acute gallbladder inflammation following BDL. Inhibition of PG synthesis could attenuate or retard the progression of early acute gallbladder inflammation if started prior to development of established disease.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Cholecystitis; Common Bile Duct; Dinoprostone; Disease Models, Animal; Gallbladder; Indomethacin; Ligation; Male; Prostaglandins; Rabbits