Efficacy and safety of the first-in-class imidazoline-2 receptor ligand CR4056 in pain from knee osteoarthritis and disease phenotypes: a randomized, double-blind, placebo-controlled phase 2 trial.

OBJECTIVE: CR4056 is a selective imidazoline-2 (I2) receptor ligand with potent analgesic activity in animal pain models. This proof-of-concept study tested CR4056 efficacy and safety in patients with knee osteoarthritis (OA) and different phenotypes. DESIGN: This is a multicenter, randomized, double-blind, placebo-controlled trial. Knee OA patients with moderate to severe pain received CR4056 (women 100 mg bid; men 200 mg bid) or placebo (both genders) for 14 days. The primary outcome was the change in WOMAC pain score (0-100 scale) compared to placebo, analyzed in the intention-to-treat population and pre-defined OA phenotypes. RESULTS: 213 patients were treated with CR4056 (92 women; 52 men) or placebo (69 overall). After 14 days, median WOMAC pain improvements were 10 points on placebo and 14, 20 and 16 in women, men, and pooled CR4056 groups (P = 0.184, 0.030 and 0.070 vs placebo, respectively). Pre-specified subgroup analysis in the metabolic OA phenotype (BMI ≥ 27.5 kg/m2, N = 156) showed statistically significant differences in all CR4056-treated groups vs placebo of 12-18 points. Conversely, there were too few patients with a neuropathic or inflammatory phenotype for a meaningful analysis. CR4056 was well tolerated; the most common adverse event was mild headache. CONCLUSIONS: Although the primary endpoint was met in males only, this exploratory phase 2 trial shows that CR4056 might be an effective analgesic against knee OA pain, especially in overweight patients representing the metabolic OA phenotype. These findings, along with the broad-spectrum analgesic activity of CR4056 in animal models, warrant further clinical investigation in OA and other pain conditions. CLINICAL TRIAL REGISTRATION NUMBER: EudraCT 2015-001136-37.

Targeting of ADAMTS5's ancillary domain with the recombinant mAb CRB0017 ameliorates disease progression in a spontaneous murine model of osteoarthritis.

OBJECTIVE: ADAMTS5 (aggrecanase-2) has been demonstrated to be crucial in the development of osteoarthritis (OA), by use of several mouse mutants carrying either truncated, catalytically inactive enzymes or aggrecanase-resistant mutant aggrecan. We have selected recombinant monoclonal antibodies directed against ADAMTS5, by using Intracellular Antibody Capture Technology (IACT). CRB0017 revealed very high affinity for the enzyme in Biacore analyses and very good specificity in a panel of binding assays. Therefore, we tested CRB0017 in a relevant spontaneous OA model, the STR/ort mouse. DESIGN: STR/ort male mice were recruited at 5 months of age, and treated intra-articularly in each knee with CRB0017 1.2 µg, CRB0017 12 µg, or vehicle. After 6 weeks, the intra-articular administration of CRB0017 was repeated with the same doses. After 3 months from recruitment, the animals were sacrificed and the femorotibial joints processed for histology and scored in a blind fashion according to both Mankin's and the OARSI methods. RESULTS AND CONCLUSIONS: All histological scores were significantly decreased in the CRB0017 12 µg/knee group compared to vehicle, while administration of CRB0017 1.2 µg was associated with a trend to a decrease in the same parameters. Therefore, CRB0017 administered twice in 3 months could modify the course of OA in the STR/ort mouse, by delaying cartilage breakdown as assessed histologically. The procedure of blind scoring of the histological samples clearly showed that knee intra-articular administration of CRB0017, an anti-ADAMTS5 antibody, dose-dependently improved disease progression in a relevant animal model of OA.

The need for a transparent, ethical, and successful relationship between academic scientists and the pharmaceutical industry: a view of the Group for the Respect of Ethics and Excellence in Science (GREES).

UNLABELLED: This paper provides recommendations for fair and unbiased relationship between academic scientists and the pharmaceutical industry. INTRODUCTION: Real or perceived problems in the relationship between academics and the industry have been the subject of much recent debate. It has been suggested that academic clinicians should sever all links with the industry-a view that is rarely challenged. METHODS: Academic experts and members of the pharmaceutical industry were invited to an expert consensus meeting to debate this topic. This meeting was organized by the Group for the Respect of Ethics and Excellence in Science. Conflict of interest, competing interest, right and duties of academic scientist, authorship, and staff and student education were discussed. RESULTS: Guidelines for a transparent, ethical, strong, and successful partnership between the academic scientist and the pharmaceutical industry have been provided. CONCLUSIONS: The Group support interactions between the industry and clinicians provided that it is transparent and ethical.

Glutamate signaling in chondrocytes and the potential involvement of NMDA receptors in cell proliferation and inflammatory gene expression.

OBJECTIVE: Increased levels of glutamate, the main excitatory neurotransmitter, are found in the synovial fluid of osteoarthritis (OA) patients. Our aim was to study glutamate signaling in chondrocytes, focusing on the composition, pharmacology, and functional role of N-methyl-d-aspartate (NMDA) glutamate receptors. METHODS: We used the human chondrocyte cell line SW1353 and, in parallel, primary rat articular chondrocytes. Glutamate release and uptake were measured by fluorimetric and radiometric methods, respectively. Gene expression was analyzed by quantitative polymerase chain reaction. NMDA receptor pharmacology was studied in binding experiments with [3H]MK-801, a specific NMDA receptor antagonist. RNA interference was used to knock-down the expression of NR1, a subunit of NMDA receptors. RESULTS: Glutamate release, sodium- and calcium-dependent glutamate uptake, and the expression of a glutamate transporter were observed in chondrocytes. NR2D was the most abundant NMDA receptor subunit in these cells. Consistent with this observation, the binding affinity of [3H]MK-801 was much lower in chondrocytes than in rat brain membranes (mean K(d) values of 700 and 2.6 nM, respectively). NR1 knock-down, as well as NMDA receptor blockade with MK-801, reduced chondrocyte proliferation. Interleukin (IL)-1beta significantly altered glutamate release and uptake (about 90% increase and 50% decrease, respectively, in SW1353 cells). Moreover, IL-1beta induced the gene expression of cytokines and enzymes involved in cartilage degradation, and MK-801 significantly inhibited this response. CONCLUSIONS: Our findings suggest that chondrocytes express a self-sufficient machinery for glutamate signaling, including a peripheral NMDA receptor with unique properties. This receptor may have a role in the inflammatory process associated with cartilage degradation, thus emerging as a potential pharmacological target in OA.

Andolast acts at different cellular levels to inhibit immunoglobulin E synthesis.

The anti-asthmatic agent andolast is thought to inhibit the release of allergic mediators, but its mechanism of action is not fully understood. We investigated whether the compound inhibits immunoglobulin E (IgE) synthesis and tested the hypothesis that andolast affects immunoglobulin class switching. Interleukin (IL)-4 and the interaction of CD40 expressed on B cells with its ligand on T cells are necessary for IgE synthesis. Thus, peripheral blood mononuclear cells (PBMCs) from 40 asthmatic, 16 non-asthmatic allergic, and 9 normal donors were stimulated with IL-4 and/or anti-CD40 antibody. T cells from 9 additional allergic donors were activated with anti-CD3/CD28 antibodies to express IL-4 mRNA. After incubation in the absence or presence of test compounds, immunoglobulin concentrations were measured by enzyme immunoassay, and mRNA levels were analyzed by RT-PCR. Andolast significantly inhibited IgE synthesis by stimulated PBMCs from both asthma patients and combined allergic/normal donors. In mechanistic studies, andolast was found to act at different cellular levels. Firstly, it reduced by about 45 percent (p<0.05) the levels of IL-4 mRNA in T cells stimulated with anti-CD3/CD28. Secondly, andolast reduced by about 36 percent (p<0.05) the expression of epsilon germline transcripts in PBMCs stimulated with IL-4/anti-CD40. Thirdly, the effect of andolast on immunoglobulin synthesis was selective in that the production of IgG4 antibodies was not significantly inhibited. Our findings, while supporting the evidence that andolast is effective for the treatment of asthma, provide new insights into its mechanism of action.

Effects of a cholecystokinin receptor antagonist on intestinal phase of pancreatic and biliary responses in man.

The present study was designed (a) to characterize the activity of loxiglumide as a peripheral cholecystokinin (CCK) antagonist in healthy human subjects, and (b) to determine whether CCK is a physiologic regulator of the intestinal phase of meal-stimulated exocrine pancreatic and biliary secretions in man. Intravenous loxiglumide (22 mumol/kg per h) was highly potent in antagonizing CCK8-induced pancreatic enzyme and bile acid secretion as well as pancreatic polypeptide release. The potency and selectivity of loxiglumide as an antagonist of CCK provides the tool for evaluating the role of CCK as a physiological mediator of meal-induced pancreatic and biliary responses in humans. Infusion of a liquid test meal into the duodenum evoked an immediate response of pancreatic enzyme and bilirubin outputs, respectively. Intravenous loxiglumide significantly inhibited the meal-induced pancreatic amylase output by 63% (P less than 0.05), lipase output by 43% (P less than 0.05), and bilirubin output by 59% (P less than 0.05). These data suggest that CCK is a physiological mediator of the intestinal phase of meal-stimulated pancreatic and biliary responses.

Antiproliferative effects of gastrin receptor antagonists and antibodies to gastrin on human colon carcinoma cell lines.

The gastrointestinal hormone gastrin has been shown to stimulate the growth of normal colonic mucosa. To examine for a possible role of gastrin in the proliferation of cultured colon tumor cells, we have studied the effects of two gastrin receptor antagonists, proglumide and benzotript, and of antibodies to gastrin. We find that proglumide (50% effective concentration, 2 to 5 mM) and benzotript (50% effective concentration, 0.4 to 0.8 mM) inhibit the monolayer growth of six human colon cancer cell lines. Addition of exogenous gastrin abrogated the growth-inhibitory effect of proglumide. The anchorage-independent growth of colon carcinoma cells was also inhibited by the two gastrin antagonists. Also, a dose-dependent increase in carcinoembryonic antigen secretion was observed upon treatment with proglumide and benzotript in three cell lines examined. Half-maximal inhibition of labeled gastrin binding was observed at concentrations of 0.4 mM benzotript and 8.6 mM proglumide. In addition, antigastrin antiserum added to HCT 116 cells adapted to growth in serum-free medium resulted in a concentration-dependent inhibition of cellular proliferation. These data suggest that gastrin may function as an autocrine growth factor in colon carcinoma.

Modulation by CR-1409 (lorglumide), a cholecystokinin receptor antagonist, of trypsin inhibitor-enhanced growth of azaserine-induced putative preneoplastic lesions in rat pancreas.

Feeding of raw soya flour or other trypsin inhibitors such as camostate is a well-established method for promoting growth of (pre)neoplastic foci induced in the exocrine pancreas of rats by azaserine. The effect of trypsin inhibitors is thought to be mediated through an increased release of cholecystokinin. Using the specific cholecystokinin receptor antagonist lorglumide (CR-1409), we performed a 16-wk study to investigate the potential of this drug in inhibiting growth of putative preneoplastic foci and to determine whether and to what extent cholecystokinin is responsible for the effect of trypsin inhibitors on pancreatic growth. After initiation with 30 mg/kg of azaserine at 19 days of age, six groups of 15 rats each received one of the following treatments: camostate, cholecystokinin-8, or gelatin control, either or not in combination with CR-1409, once daily, 3 days wk for 16 wk. Plasma cholecystokinin levels, measured 30 min after the stimulus, were similar after camostate and cholecystokinin octapeptide administration. After 16 wk the pancreata were removed, weighted, and quantitatively analyzed for the number and size of putative preneoplastic foci by light microscopy. Both camostate and cholecystokinin octapeptide stimulated pancreatic growth and development of acidophilic putative preneoplastic foci, whereas growth of basophilic putative preneoplastic foci was inhibited by camostate but stimulated by cholecystokinin. CR-1409 almost completely abolished the effect of cholecystokinin and was found to cause a significant decrease in the effects of camostate. It is concluded that (a) cholecystokinin plays a significant role in camostate-stimulated growth of acidophilic putative preneoplastic foci in rat pancreas and (b) CR-1409 inhibits growth of putative preneoplastic foci induced in rat pancreas by azaserine and hence may be of potential value for the treatment of pancreatic cancer in humans.

Evaluation of Levothyroxine Bioavailability after Oral Administration of a Fixed Combination of Soy Isoflavones in Post-menopausal Female Volunteers.

BACKGROUND: Post-menopausal women under treatment with levothyroxine for their medical conditions may take concomitantly dietary supplements containing soy isoflavones in combination to treat their post-menopausal symptoms. The aim of this study was to investigate the effect of a fixed combination of soy isoflavones on the oral bioavailability of levothyroxine in post-menopausal female volunteers. METHODS: 12 healthy post-menopausal female, who were on stable oral levothyroxine as replacement/supplementation therapy for hypothyroidism, received a single recommended oral dose of a food supplement containing 60 mg of soy isoflavones (>19% genistin and daidzin) concomitantly with (test) and 6 h later (reference) the administration of levothyroxine in a randomized, open label, crossover fashion. Plasma concentrations of levothyroxine and soy isoflavones (daidzin, daidzein, genistin, genistein, S-equol) were determined by LC-MS/MS. Pharmacokinetic (PK) parameters were determined by non-compartmental analysis. No effect of soy isoflavones was assumed if the 90% confidence intervals (CIs) for the estimated ratio test/reference was included in the acceptance limits 0.80-1.25 for PK parameters Cmax and AUCt. RESULTS: The test/reference ratios Cmax and AUCt of levothyroxine were very close to unity (1.02 and 0.99, respectively) and the corresponding 90% CIs (0.99-1.04 and 0.88-1.12, respectively) fell entirely within the acceptance bioequivalence limits. CONCLUSION: The combination of soy isoflavones used in the present investigation does not affect the rate and extent of levothyroxine absorption when administered concomitantly in post-menopausal women.

Bombesin reduces food intake in lean man by a cholecystokinin-independent mechanism.

This double blind study was undertaken to determine whether infusion of bombesin (BBS) inhibits the intake of a carbohydrate-rich meal in nine lean healthy subjects and whether inhibition of food intake by BBS is mediated by cholecystokinin (CCK). During infusion of BBS, the amount of food eaten was decreased compared to that after saline infusion (482 +/- 74 vs. 602 +/- 68 g; P < 0.01). Subjective criteria of satiation were also significantly affected by BBS infusion (P < 0.05). Administration of the CCK receptor antagonist loxiglumide (CR1505) to six of the subjects did not prevent the decrease in food intake due to BBS (365 +/- 69 g) or the subjective criteria for satiety. Furthermore, the amount of food eaten during loxiglumide treatment alone (537 +/- 109 g) was not different from that during control saline infusion. In conclusion, infusion of BBS inhibits the intake of a carbohydrate-rich meal by a CCK-independent mechanism.

Satiety effects of the type A CCK receptor antagonist loxiglumide in lean and obese women.

Several studies have demonstrated that administration of cholecystokinin (CCK) reduces food intake in several species, including humans. In animal studies CCK-receptor antagonists have been reported to increase food intake, suggesting a physiological satiety effect of CCK in these animals. In a double-blind, placebo-controlled study, we investigated the effect of the specific CCK-A receptor antagonist loxiglumide on food intake (carbohydrate-rich meal) and on subjective hunger feelings scored with visual analogue scales and food selection lists in seven healthy obese women and in seven healthy lean women. Loxiglumide was administered intravenously in a dose of 10 mg/kg ideal weight/h. For the whole group, food intake during loxiglumide (359 +/- 39 g) was not significantly different from food intake during saline infusion (333 +/- 31 g). Also, when the lean and obese subgroups were analyzed separately, no significant influence of loxiglumide on food intake was found. In addition, no significant differences in satiety scores were seen using the food selection lists or visual analogue scales. In conclusion, in the present study during infusing the CCK-A receptor antagonist loxiglumide we found no increase in preprandial satiety nor in food intake of a carbohydrate-rich meal nor in postprandial satiety in lean and obese women.

Effect of a cholecystokinin antagonist on some effects of diazepam.

Dose responses were evaluated for the effects of diazepam alone or together with the cholecystokinin receptor antagonist CR 1409 on pentetrazole-induced convulsions, motor performance and spontaneous motor activity. The results obtained showed that the cholecytokinin antagonist potentiated the effects of diazepam on motor performance and the anticonvulsant activity of diazepam, while it did not affect spontaneous motor activity. The data presented are consistent with a role for cholecystokinin in some effects of diazepam.

Antiallergic and cytoprotective activity of new N-phenylbenzamido acid derivatives.

A series of new N-phenylbenzamido acid derivatives was synthesized and evaluated for their ability to inhibit the IgE-mediated passive cutaneous anaphylaxis in the rat (PCA), as well as for their capacity to inhibit gastric mucosal damage induced by the oral administration of absolute alcohol in the rat. Some of these new derivatives exhibit potent antiallergic and cytoprotective activity, 20-80 times higher than that of the reference, disodium cromoglycate (DSCG). Structure-activity relationships are discussed. The antiallergic activity of one of the more potent compounds of this series, i.e. 4-(1H-tetrazol-5-yl)-N-[4-(1H-tetrazol-5-yl)phenyl]benzamide (compound 44, CR 2039) was further evaluated in vivo. This compound antagonizes the bronchoconstriction induced by aerosolized ovalbumin in both anesthetized and conscious IgE sensitized guinea pigs with ID50 of 3.7 mg/animal (tracheal insufflation) and 20 mg/kg (im). Further cytoprotective effects were evaluated in gastric ulcer models induced by the acute oral administration of hypertonic sodium chloride solution or by acetic acid and by the subchronic administration of glucose in fasted animals. In the models used experimentally CR 2039 is effective, whereas DSCG seems to be devoid of any protective activity. Such a potent antiallergic and mucosal protectant could provide a new potential agent in the therapy of atopic allergic diseases.

Structure-antigastrin activity relationships of new (R)-4-benzamido-5-oxopentanoic acid derivatives.

New (R)-4-benzamido-5-oxopentanoic acid derivatives were synthesized by a stereoconservative procedure and evaluated in vitro for their capacity to inhibit the binding of [125I](BH)-CCK-8 to either rat peripheral (CCK-A) or central (CCK-B) CCK receptors, or the binding of [3H]pentagastrin to rabbit gastric glands, as well as to inhibit, in vivo, the acid secretion induced by pentagastrin infusion in the perfused rat stomach. The parent compound of this series (lorglumide) is the first nonpeptidic, potent and selective antagonist of the CCK-A receptor. Chemical manipulations of the structure of lorglumide led to the discovery of selective antagonists of the CCK-B/gastrin receptors. Structure-activity relationships are discussed. Some of these new derivatives exhibit different affinities with rabbit gastric gland cells and rat cortex membranes, suggesting that the stomach gastrin receptor (arbitrarily termed CCK-B1 receptor) is not as closely related to the CCK central receptor (termed CCK-B2) as previously hypothesized. The antigastric activity of the most potent compound of the series, i.e. (R)-4-(3,5-dichlorobenzamido)-5-(8-azaspiro[4.5]decan- 8-yl)-5-oxopentanoic acid (compound 28, CR 2194) was further evaluated in vivo: in the first hour after administration the compound inhibits acid secretion induced by pentagastrin infusion, in both cat and dog (in the cat with gastric fistula and in the dog with Heidenhain pouch), with ID50s (mg/kg) of 15.5 (iv) (cat), 8.7 (IV) (dog) and 24.2 (oral) (Heidenhain dog). The characteristics of CR 2194, that is, the selectivity for the gastrin receptor, the simple nonpeptidic molecular structure, and the activity after oral administration, indicate that this compound is a useful tool in the study of the biological effects of gastrin and a potential agent for diagnostic or therapeutic use.

Effects of the synthetic trypsin inhibitor camostate on the development of N-nitrosobis(2-oxopropyl)amine-induced pancreatic lesions in hamsters.

Trypsin inhibitors have been shown to promote pancreatic growth as well as the development of pancreatic tumours in rats. The present study was carried out to examine the effects of the synthetic trypsin inhibitor camostate on the growth of the pancreas and on the development of pancreatic preneoplastic and neoplastic lesions in hamsters treated with N-nitrosobis(2-oxopropyl)amine. A specific cholecystokinin-receptor antagonist was administered to determine the role of cholecystokinin in camostate action. The animals were killed 19 weeks after the first injection with N-nitrosobis(2-oxopropyl)amine. Camostate caused an increase in growth of the pancreas and a decrease in the number of (pre)neoplastic ductular pancreatic lesions. Lorglumide (CR-1409) did not influence these effects of camostate. It was concluded that rats and hamsters behave differently with regard to the effect of camostate on pancreatic growth and carcinogenesis.

Effects of bombesin on the development of N-nitrosobis(2-oxopropyl)amine-induced pancreatic lesions in hamsters.

Bombesin (BBS) has been shown to promote pancreatic growth as well as the development of pancreatic (pre)neoplasia in rats. The present study was carried out to determine the effects of bombesin on pancreatic growth and on the development of pancreatic (pre)neoplastic lesions in hamsters treated with N-nitrosobis(2-oxopropyl)amine (BOP). Bombesin caused an increase in growth of the pancreas accompanied by a decrease in the number of (pre)neoplastic ductular pancreatic lesions. Lorglumide (CR-1409) did not influence these effects of bombesin. It is concluded that in BOP-treated hamsters the effect of bombesin on the pancreas is not mediated by cholecystokinin (CCK). These data support the existence of species difference between rats and hamsters with regard to the effect of bombesin on pancreatic carcinogenesis.

Proopiomelanocortin, Preproenkephalin-A and Preprocholecystokinin mRNA in the Hypothalamus of CCI-Treated Rats.

It has previously been shown that beta-endorphin (BE) and cholecystokinin (CCK) concentrations decrease in brain areas of rats or humans affected by severe liver disease (SLD). We now report the increase of proopiomelanocortin (POMC) and preprocholecystokinin mRNA in the hypothalamus and cortex of rats with experimental SLD, suggesting an increased post-translational turnover of BE and CCK in this experimental condition.

Monitoring bone effect of transdermal hormone replacement therapy by ultrasound investigation at the phalanx: a four-year follow-up study.

OBJECTIVE: A controlled 4-year follow-up study was conducted on a population composed of 112 healthy early postmenopausal women to evaluate the ability of ultrasound technology in detecting the effects of hormone replacement therapy (HRT) on bone. At the end of the study, 47 untreated and 25 treated women had been evaluated. Cyclic sequential estrogen/progestogen therapy, 50 microg/day of transdermal 17beta-estradiol (Rotta Research Laboratorium) plus 5 mg/day of medrogestone (Wyeth-Ayerst) was used. DESIGN: Ultrasound transmission through the distal metaphysis of hand phalanxes was measured by DBM Sonic. Beside amplitude-dependent speed of sound (AD-SoS), three new parameters could be calculated: pure speed of sound (pSOS), bone transmission time (BTT), and ultrasound bone profile index (UBPI). Ultrasound measurements were taken at baseline and after 1, 2, and 4 years. RESULTS: Among untreated women a significant decrease of all ultrasound parameters was observed at follow-up measurements. In the HRT-treated group we observed a significant increase of AD-SoS, pSoS, and BTT. We qualified as "responders" women in the treated group for whom AD-SoS, pSoS, and BTT increased by more than 2.77 times the coefficient of variation of the measurement, i.e., 95% variability. Women in the treated group were identified as responders at 4 years of follow-up by AD-SoS (56%), pSOS (56%), and BTT (60%). Ultrasound bone profile index declined in both groups, although to a lower extent among HRT-treated subjects. CONCLUSIONS: The 4-year data confirm the results obtained at 1 and 2 years of follow-up. This study demonstrates that bone tissue investigation by ultrasound at the phalanx can be used to monitor the effect of HRT, and thus it should be considered a potential technology for the management of menopause by gynecologists.

Protective effect of CR 1409 (cholecystokinin antagonist) on experimental pancreatitis in rats and mice.

CR 1409, a glutaramic acid derivative with competitive cholecystokinin-antagonistic activity, was administered IP and evaluated in comparison with proglumide (the model CCK-receptor antagonist), gabexate (protease inhibitor) and PGE2 (cytoprotective) on two different models of experimental pancreatitis. Acute pancreatitis was induced in mice by six IP injections of 50 micrograms/kg caerulein at hourly intervals. The drugs were administered 30 minutes before each caerulein administration. Blood samples and pancreata were collected 3 hours after the last caerulein injection. In the second experiment, pancreatitis was induced in rats by injecting 0.3 ml 6% sodium taurocholate interstitially into the pancreas. The drugs were administered twice, 30 minutes before and 3 hours after taurocholate. The animals were killed 6 hours after laparotomy and blood samples and pancreata were collected. CR 1409 exhibited on both pancreatitis models a protective effect in a dose range of 0.3-10 mg/kg. Proglumide exhibited a protective activity at higher doses (200-400 mg/kg). Gabexate and PGE2 were effective only in pancreatitis induced by taurocholate in a dose range of 30-60 mg/kg and 60-130 micrograms/kg respectively. These results, showing a high protective effect of CR 1409 on different models of acute pancreatitis, suggest an important role of CCK in the pathogenesis of pancreatitis.

Effect of the specific cholecystokinin-receptor antagonist loxiglumide on bombesin stimulated pancreatic enzyme secretion in man.

We have investigated the effects of the specific cholecystokinin (CCK) receptor antagonist loxiglumide on basal and bombesin stimulated pancreatic enzyme secretion, bilirubin output and plasma CCK release in six healthy subjects. The data were compared with those obtained in control experiments where saline was infused instead of loxiglumide. Basal amylase output (4.7 +/- 0.8 kU/45 min), trypsin output (2.9 +/- 0.8 kU/45 min) and bilirubin output (7.7 +/- 2.8 mmol/45 min) gradually declined during infusion of loxiglumide to values of 1.3 +/- 0.3 kU/45 min, 0.5 +/- 0.1 kU/45 min and 0.4 +/- 0.0 mmol/45 min, respectively, reaching statistical significance (P less than 0.05) in the 30 to 45-min period after the start of the loxiglumide infusion. In the control experiments saline infusion failed to influence basal amylase, trypsin and bilirubin output, while bombesin stimulated amylase output from 4.7 +/- 0.8 kU/45 min to 25.1 +/- 5.1 kU/45 min (P less than 0.05), trypsin output from 2.9 +/- 0.8 kU/45 min to 11.6 +/- 2.0 kU/45 min (P less than 0.05) and bilirubin output from 7.7 +/- 2.8 mmol/45 min to 68.0 +/- 16.0 mmol/45 min (P less than 0.05). Loxiglumide failed to significantly influence bombesin stimulated amylase output (36.7 +/- 9.0 kU/45 min) and trypsin output (8.3 +/- 2.9 kU/45 min), but almost abolished bilirubin output (9.7 +/- 3.6 mmol/45 min) (P less than 0.05). Basal plasma CCK (2.4 +/- 0.1 pM) was not significantly influenced by loxiglumide (2.4 +/- 0.2 pM).(ABSTRACT TRUNCATED AT 250 WORDS)