devazepide and lorglumide

The effects of oxytocin on gastric emptying, gastrointestinal transit, and plasma levels of cholecystokinin (CCK) were studied in ovariectomized rats. Gastrointestinal motility was assessed in rats 15 min after intragastric instillation of a test meal containing charcoal and Na2 51CrO4. Gastric emptying was determined by measuring the amount of radiolabeled chromium contained in the small intestine as a percentage of the initial amount received. Gastrointestinal transit was evaluated by calculating the geometric center of distribution of the radiolabeled marker. Blood samples were collected for CCK radioimmunoassay. After administration of oxytocin (0.2-0.8 mg/kg), gastric emptying and gastrointestinal transit were inhibited, whereas plasma concentration of CCK was increased in a dose-dependent manner. Atosiban, an oxytocin receptor antagonist, effectively attenuated the oxytocin-induced inhibition of gastric emptying and gastrointestinal transit. However, administration of atosiban alone had no effect on gastric emptying and gastrointestinal transit. The selective CCK1 receptor antagonists, devazepide and lorglumide, effectively attenuated the oxytocin-induced inhibition of gastric emptying and gastrointestinal transit. L-365, 260, a selective CCK2 receptor antagonist, did not alter the oxytocin-induced inhibition of gastric emptying and gastrointestinal transit. These results suggest that oxytocin inhibits gastric emptying and gastrointestinal transit in ovariectomized rats via a mechanism involving the stimulation of CCK release and CCK1 receptor activation.

Topics: Animals; Benzodiazepinones; Cholecystokinin; Devazepide; Dose-Response Relationship, Drug; Eating; Female; Gastric Emptying; Gastrointestinal Motility; Gastrointestinal Transit; Ovariectomy; Oxytocin; Phenylurea Compounds; Proglumide; Radioimmunoassay; Rats; Rats, Sprague-Dawley; Receptor, Cholecystokinin A; Receptors, Cholecystokinin; Receptors, Oxytocin; Sincalide; Vasotocin

Some data suggest that cholecystokinin (CCK) receptor agonists stimulate the growth of colon cancer. Melatonin, an endogenous indoleamine with strong antioxidant properties, displays antiproliferative and proapoptotic properties both in vivo or in vitro in several types of tumors. We used HT-29 human colon cancer cells, expressing CCK receptors, to test the antiproliferative effects of several antagonists of CCK-A and/or CCK-B and their possible synergism with melatonin. HT-29 cells were cultured in RPMI 1640 medium supplemented with fetal bovine serum at 37 degrees C. Cell proliferation was assessed by the incorporation of [3H]-thymidine into DNA. Annexin V-FITC plus propidium iodine were used for flow cytometry apoptosis/necrosis evaluation. The following drugs were tested: gastrin (CCK-B agonist); CCK-8s (CCK-A agonist); proglumide (CCK-A plus CCK-B antagonist); lorglumide (CCK-A antagonist); PD 135,158 (CCK-B antagonist and weak CCK-A agonist); devazepide or L 364,718 (CCK-A antagonist); L 365,260 (CCK-B antagonist), and melatonin. The results shown a lack of effects of gastrin on HT-29 cell proliferation, whereas CCK-8s induced proliferation at high doses. The order of the antiproliferative effect of the other drugs was devazepide > lorglumide > proglumide. These drugs produce cell death mainly inducing apoptosis. Melatonin showed strong antiproliferative effect at millimolar concentrations, and it induced apoptotic cell death. Melatonin generally enhanced the antiproliferative effects of devazepide, lorglumide and proglumide and increased the proglumide-induced apoptosis. These results suggest that melatonin and CCK-A antagonists are useful for controlling human colon cancer cell growth in culture and in combined therapy significantly increases their efficiency.

Topics: Antineoplastic Agents; Apoptosis; Cell Proliferation; Devazepide; Dose-Response Relationship, Drug; Drug Synergism; Gastrins; Growth Inhibitors; HT29 Cells; Humans; Melatonin; Proglumide; Receptor, Cholecystokinin A; Receptor, Cholecystokinin B; Sincalide

The pharmacological profile of the new CCK1 receptor antagonist IQM-97,423, (4aS,5R)-2-benzyl-5-(tert-butylaminocarbonyl-tryptophyl)amino-1,3-dioxoperhydropyrido-[1,2-c]pyrimidine, was examined in in vitro and in vivo studies and compared with typical CCK1 antagonists such as devazepide and lorglumide. IQM-97,423 showed a high affinity at [3H]-pCCK8-labeled rat pancreatic CCK1 receptors, and was virtually devoid of affinity at brain CCK2 receptors. IQM-97,423 antagonized CCK8S-stimulated alpha-amylase release from rat pancreatic acini with a potency similar to devazepide and much higher than lorglumide. In the guinea pig isolated longitudinal muscle-myenteric plexus preparation, IQM-97,423 produced a full antagonism of the contractile response elicited by CCK8S and a weaker effect on the contraction elicited by CCK4, suggesting a selective antagonism at CCK1 receptors. The protective effect of IQM-97,423 and devazepide was tested in two models of acute pancreatitis in rats, induced by injection of cerulein or by combined bile and pancreatic duct obstruction. The new compound fully prevented the cerulein-induced increase in plasma pancreatic enzymes and in pancreas weight with a potency similar to devazepide. In common bile-pancreatic duct ligature-induced acute pancreatitis, IQM-97,423 partially prevented, like devazepide, the increase in plasma pancreatic enzyme activity and in pancreas weight. Consequently, the pyridopyrimidine derivative IQM-97,423 is a potent and highly selective CCK1 receptor antagonist with preventive effects in two experimental models of acute pancreatitis and a potential therapeutic interest.

Topics: Acute Disease; alpha-Amylases; Animals; Binding, Competitive; Cerebral Cortex; Cholecystokinin; Devazepide; Disease Models, Animal; Guinea Pigs; Ileum; In Vitro Techniques; Male; Mice; Muscle Contraction; Muscle, Smooth; Myenteric Plexus; Neuromuscular Junction; Pancreatitis; Peptide Fragments; Proglumide; Pyrimidinones; Rats; Rats, Wistar; Receptor, Cholecystokinin A

The effects of oxytocin (OT) on gastric emptying, gastrointestinal transit, and plasma levels of cholecystokinin (CCK) were studied in female rats. Gastrointestinal motility was assessed in rats 15 min after intragastric instillation of a test meal containing charcoal and Na(2)(51)CrO(4). Gastric emptying was determined by measuring the amount of radiolabeled chromium contained in the small intestine as a percentage of the initial amount received. Gastrointestinal transit was evaluated by calculating the geometric center of distribution of the radiolabeled marker. Blood samples were collected for CCK radioimmunoassay. After administration of OT (0.2-0.8 mg/kg), gastric emptying and gastrointestinal transit were inhibited, whereas the plasma concentration of CCK was increased in a dose-dependent manner. Atosiban, an oxytocin receptor antagonist, effectively attenuated the OT- induced inhibition of gastric emptying and gastrointestinal transit. However, administration of atosiban alone had no effect on gastric emptying and gastrointestinal transit. The selective CCK(1) receptor antagonists, devazepide and lorglumide, effectively attenuated the OT-induced inhibition of gastric emptying and gastrointestinal transit. L-365, 260, a selective CCK(2) receptor antagonist, did not alter the OT-induced inhibition of gastric emptying and gastrointestinal transit. These results suggest that OT inhibits gastric emptying and gastrointestinal transit in female rats via a mechanism involving CCK stimulation and CCK(1) receptor activation.

Topics: Animals; Benzodiazepinones; Cholecystokinin; Devazepide; Dose-Response Relationship, Drug; Female; Gastric Emptying; Gastrointestinal Agents; Gastrointestinal Transit; Hormone Antagonists; Oxytocin; Phenylurea Compounds; Proglumide; Rats; Rats, Sprague-Dawley; Receptors, Cholecystokinin; Vasotocin

In experimental conditions, golden hamsters (Mesocricetus auratus) avidly consume ethanol solutions. However, they are relatively resistant to the deleterious effects of ethanol even after months of continuous consumption, apparently because they metabolize ethanol rapidly and efficiently. Male hamsters with ad libitum access to food and water were presented with isocaloric solutions [weight/weight (wt./wt.)] of 10% ethanol and 17.75% glucose for 40-min periods on alternate days. When hamsters were injected with 0.9% saline before solution presentation the mean intake of ethanol solution (0.55 g) was about half that of glucose solution (1.08 g). Hamsters derived a mean of 0.36 g/kg/40 min of absolute ethanol from the ethanol solution, an amount that does not seem to exceed their metabolic capacity for ethanol. An intraperitoneal injection of a 2.0-microg/kg dose of the C-terminal octapeptide of cholecystokinin (CCK-8) reduced intakes of both solutions by >50% if administered 5 min before solution presentation, but it was ineffectual if administered 45 min before presentation. When citric acid (2.5 g/l) was added to the glucose solution the baseline intakes of the two solutions were virtually equivalent, and when CCK-8 was administered over a range of doses (0.5-2.0 microg/kg) the intakes of the solutions did not differ significantly at any dose, supporting the suggestion that the pharmacological properties of ethanol play little or no role in mediating the consumption-inhibiting effect of exogenously administered cholecystokinin (CCK). Prior administration of lorglumide, a selective CCK type A receptor antagonist, completely attenuated the inhibitory effect of CCK-8. Findings are consistent with the notion that endogenous CCK plays a key role in the short-term control of ethanol intake in hamsters.

Topics: Alcohol Drinking; Animals; Cholecystokinin; Cricetinae; Depression, Chemical; Devazepide; Dose-Response Relationship, Drug; Glucose; Hormone Antagonists; Male; Mesocricetus; Proglumide; Receptors, Cholecystokinin

The effects of estradiol benzoate (EB) on gastric emptying, gastrointestinal transit and plasma levels of cholecystokinin (CCK) were studied in ovariectomized rats.. Gastrointestinal motility was assessed in rats 15 min after intragastric instillation of a test meal containing charcoal and Na2 51CrO4. Gastric emptying was determined by measuring the amount of radiolabeled chromium contained in the small intestine as a percentage of the initial amount received. Gastrointestinal transit was evaluated by calculating the geometric center of distribution of the radiolabeled marker. Blood samples were collected for E2 and CCK radioimmunoassay.. After treatment of EB (4-25 microg/kg), gastric emptying and gastrointestinal transit were inhibited, whereas plasma concentrations of E2 and CCK were increased in a dose-dependent manner. The selective CCK(A) receptor antagonists, devazepide and lorglumide, effectively attenuated the EB-induced inhibition of gastric emptying and gastrointestinal transit. L-365,260, a selective CCK(B) receptor antagonist, did not alter the EB-induced inhibition of gastric emptying and gastrointestinal transit.. The results suggest that EB inhibits gastric emptying and gastrointestinal transit in ovariectomized rats via a mechanism involving CCK stimulation and CCK(A) receptor activation.

Topics: Animals; Benzodiazepinones; Cholecystokinin; Devazepide; Disease Models, Animal; Estradiol; Female; Gastric Emptying; Gastrointestinal Transit; Hormone Antagonists; Ovariectomy; Phenylurea Compounds; Proglumide; Rats; Rats, Sprague-Dawley; Receptors, Cholecystokinin; Time Factors

The agonist activities of the C-terminal cholecystokinin peptides sulfated cholecystokinin octapeptide (CCK-8S), non-sulfated cholecystokinin octapeptide (CCK-8NS), pentagastrin and CCK-4 at the cloned human CCK-A receptor expressed in Chinese hamster ovary cells were evaluated in two functional assays of receptor activation. [125I]-CCK-8S displacement studies employing membranes derived from these cells revealed the expected rank order of affinity for a number of CCK receptor ligands. CCK-8S was a potent agonist in (i) stimulating the mobilization of intracellular free Ca2+, measured with the Ca2+ sensitive fluorescent indicator FURA-2, and (ii) stimulating increases in extracellular acidification rates, measured by microphysiometry. Consistent with their lower affinities for CCK-A receptors, CCK-8NS, pentagastrin and CCK-4 were weaker agonists in both functional assays. In addition, these peptides exhibited partial agonist activity relative to the maximum response observed with CCK-8S in both assays. These results demonstrate that CCK-8S represents the minimum ligand requirement for both high affinity and full agonist activity at the human CCK-A receptor subtype.

Topics: Animals; Benzodiazepinones; Binding, Competitive; Calcium; CHO Cells; Cloning, Molecular; Cricetinae; Devazepide; Hormone Antagonists; Humans; Hydrogen-Ion Concentration; Pentagastrin; Peptide Fragments; Proglumide; Receptor, Cholecystokinin A; Receptors, Cholecystokinin; Sincalide; Tetragastrin

The effect of Gi coupled receptor activation (adenosine A1 and 5-HT1B receptors) on cholecystokinin receptor-stimulated inositol phosphate accumulation has been investigated in Chinese hamster ovary cells transfected with the human adenosine A1 receptor cDNA (CHO-A1). CHO cells constitutively express the 5-HT1B receptor [Berg, Clarke, Sailstad, Saltzman and Maayani (1994) Mol. Pharmacol. 46, 477-484]. Our previous studies using CHO-A1 cells have revealed that both the adenosine A1 and 5-HT1B receptor are negatively coupled to adenylyl cyclase activity and stimulate increases in [Ca2+]i, through a pertussis toxin-sensitive pathway. In the present study the selective adenosine A1 receptor agonist N6-cyclopentyladenosine stimulated a pertussis toxin-sensitive increase in total [3H]inositol phosphate accumulation. The sulphated C-terminal octapeptide of cholecystokinin (CCK-8) stimulated a robust and pertussis toxin-insensitive increase in [3H]inositol phosphate accumulation through the activation of CCKA receptors. Co-stimulation of CHO-A1 cells with N6-cyclopentyladenosine and CCK-8 produced a synergistic increase in [3H]inositol phosphate accumulation. The synergistic interaction between N6-cyclopentyladenosine and CCK-8 was abolished in pertussis toxin-treated cells. Synergy between N6-cyclopentyladenosine and CCK-8 still occurred in the absence of extracellular calcium. The 5-HT1B receptor agonist 5-carboxyamidotryptamine did not stimulate a measurable increase in [3H]inositol phosphate accumulation. Furthermore, 5-carboxyamidotryptamine had no significant effect on CCK-8 mediated [3H]inositol phosphate production. Activation of endogenous P2U receptors (Gq/Gll coupled) with ATP gamma S produced a significant increase in [3H]inositol phosphate accumulation. Co-stimulation of CHO-A1 cells with ATP gamma S and CCK-8 produced additive increases in [3H]inositol phosphate accumulation. These data indicate that CHO-A1 cells may prove a useful model system in which to investigate further the mechanisms underlying the intracellular 'cross-talk' between phospholipase C coupled receptors (Gq/Gll linked) and Gi/Go coupled receptors.

Topics: Adenosine; Adenylate Cyclase Toxin; Adenylyl Cyclase Inhibitors; Animals; Benzodiazepinones; Calcium; CHO Cells; Cricetinae; Devazepide; Dose-Response Relationship, Drug; Drug Synergism; Hormone Antagonists; Humans; Inositol Phosphates; Pertussis Toxin; Proglumide; Receptors, Purinergic P1; Receptors, Serotonin; Sincalide; Virulence Factors, Bordetella

1. The cardiovascular actions of cholecystokinin and related peptides were investigated in the pithed rat. The receptors and the mechanisms involved in these experiments were characterized. 2. Sulphated cholecystokinin octapeptide (sCCK-8, 0.1-100 nmol kg-1, i.v.) elicited a dose-dependent bradycardia and increase in mean arterial blood pressure. Neither gastrin-17 nor pentagastrin had any effect at concentrations up to 100 nmol kg-1. 3. Both the pressor response and bradycardia elicited by sCCK-8 were reduced by the selective CCKA receptor antagonists, devazepide (0.5-50 nmol kg-1) and lorglumide (1-7 mumol kg-1). The selective CCKB receptor antagonists, CI-988 (1 mumol kg-1) and L-365,260 (15 mumol kg-1) did not inhibit the effects of sCCK-8. 4. The pressor response induced with sCCK-8 was reduced by treatment with either phentolamine (3 mumol kg-1) or guanethidine (2 mumol kg-1) and was unaffected by treatment with propranolol, atropine or hexamethonium. The pressor response also persisted following bilateral adrenalectomy. 5. The bradycardia induced with sCCK-8 was unaffected by treatment with phentolamine, propranolol, guanethidine, atropine, hexamethonium or bilateral adrenalectomy. 6. The tetrapeptide of cholecystokinin (CCK-4) elicited a dose-dependent pressor response but did not induce bradycardia. The pressor response was unaffected by devazepide (50 nmol kg-1), L-365260 (15 mumol kg-1) or phentolamine (3 mumol kg-1). 7. In the pithed rat, sCCK-8 acted via CCKA receptors to increase arterial blood pressure indirectly, at least in part, through activation of alpha-adrenoceptors. The observed bradycardia was also mediated byCCKA receptors but possibly through a direct action on the heart.

Topics: Adrenalectomy; Adrenergic Agents; Animals; Benzodiazepinones; Blood Pressure; Bradycardia; Cholecystokinin; Decerebrate State; Devazepide; Dose-Response Relationship, Drug; Gastrins; Guanethidine; Heart Rate; Hormone Antagonists; Hormones; Hypertension; Indoles; Male; Meglumine; Pentagastrin; Phentolamine; Proglumide; Rats; Receptors, Cholecystokinin; Sincalide; Tetragastrin

The ability of CCKA antagonists to inhibit full and partial CCK agonists of the rat pancreatic acinar cell CCKA receptor has been studied. When isolated rat pancreatic acini were superfused with CCK-8 (10 pM-1 nM) or CCK-4 (1 microM), an increase in [Ca2+]i signal was initiated. Concurrent superfusion of either L-364,718 (0.1 microM) or lorglumide (10 microM), chemically distinct, specific, potent antagonists of the CCKA receptor, resulted in a rapid inhibition of the [Ca2+]i signal initiated by all concentrations of CCK-8. In contrast, Ca2+ oscillations, initiated by JMV-180 (25 nM-1 microM), a partial agonist analogue of CCK-8, were essentially unaffected by concurrent superfusion of either L-364,718 or lorglumide. When JMV-179, an analogue of JMV-180 that exhibits characteristics of a pure antagonist, was superfused concurrently with either CCK-8 or JMV-180, Ca2+ oscillations were inhibited, even in the presence of 0.1 microM L-364,718. In a similar fashion, amylase secretion stimulated by CCK-8 was markedly attenuated by L-364,718, lorglumide, and JMV-179, whereas secretion stimulated by JMV-180 was only inhibited by JMV-179. A model is proposed to reconcile this data, based on the assumption that JMV-180 and CCK-8 interact with discrete sites on the CCKA receptor, which are differentially affected by the binding of antagonists. This model may also explain how a single receptor may transduce multiple signals in response to different agonists.

Topics: Amino Acid Sequence; Amylases; Animals; Benzodiazepinones; Calcium; Cholecystokinin; Devazepide; Male; Models, Biological; Molecular Sequence Data; Pancreas; Periodicity; Proglumide; Rats; Rats, Sprague-Dawley; Receptor, Cholecystokinin A; Receptors, Cholecystokinin; Signal Transduction; Sincalide

The role of gastrin in the control of growth of renal G401 cells isolated from a human nephroblastoma (Wilms' tumour) was investigated. G401 cell growth was enhanced in the presence of exogenous gastrin. Addition of anti-gastrin antibodies to serum-free medium significantly inhibited the growth of G401 cells. G401 cells contained the equivalent of 4.3 pg/10(6) cells of gastrin, and serum-free medium collected over 48 hr from G401 cells contained the equivalent of 38 ng/10(6) cells of gastrin, as determined by radioimmunoassay. Growth of G401 cells was inhibited in a concentration-related way by a variety of gastrin/CCK receptor antagonists. Devazepide and proglumide were, respectively, the most and the least potent inhibitors of G401 cell growth (potency order devazepide > L-365,260 = lorglumide > loxiglumide > benzotript > proglumide). These gastrin/CCK receptor antagonists had similar growth-inhibitory activities in human colonic adenocarcinoma HCT-116 cells. Growth of HCT-116 cells was stimulated to a lesser extent, as compared with G401 cells, by exogenous gastrin, and endogenous gastrin was not detectable in HCT-116 cells. The results are consistent with a role for a gastrin-like peptide in the control of growth of a renal cell line. The data suggest that gastrin/CCK receptor antagonists warrant further investigation as therapeutic agents for the control of gastrin-responsive tumours derived from outside, as well as inside, the gastrointestinal tract, including tumours derived from the kidney.

Topics: Benzamides; Benzodiazepinones; Cell Division; Devazepide; Gastrins; Humans; Indoles; Kidney Neoplasms; Meglumine; Phenylurea Compounds; Proglumide; Receptors, Cholecystokinin; Tumor Cells, Cultured; Wilms Tumor

Cholecystokinin (CCK) plays an important role in gallbladder contraction and gut motility. Sincalide (CCK-8) evoked guinea pig isolated ileum contraction at 10(-5)-10(-1) mumol.L-1 in a concentration-dependent manner, EC50 being 207 pmol.L-1. It delayed the gastric emptying as well. The rate of inhibition of gastric emptying was 71 +/- 12% at 100 micrograms.kg-1 by ip. Sincalide antagonists: lorglumide, devazepide, and L-365,260 antagonized the ileal smooth muscle response to sincalide in a concentration-dependent manner. Their pA2 were 7.30, 10.02, and 7.77, respectively. Lorglumide, devazepide, and L-365,260 inhibited the delaying of gastric emptying evoked by sincalide. The IC50 were 0.11, 0.0064, and 0.66 mg.kg-1, respectively.

Topics: Animals; Benzodiazepinones; Devazepide; Gastric Emptying; Gastrointestinal Motility; Guinea Pigs; Ileum; Male; Muscle Contraction; Muscle, Smooth; Phenylurea Compounds; Proglumide; Rats; Rats, Sprague-Dawley; Receptors, Cholecystokinin; Sincalide

A series of novel nonpeptide cholecystokinin-A (CCK-A) antagonists have been synthesized. Designed on the basis of the structural homology between lorglumide and L-364,718, as investigated with molecular modeling, these compounds constitute a link between the N-acylglutamic acid and 3-amino-5-phenyl-1,4-benzodiazepin-2-one derived antagonists. The prepared compounds were tested in vitro as antagonists of the binding of [3H]-(+/-)-L-364,718 and [3H]-CCK-8(S) to rat pancreas and guinea pig brain membranes, respectively. All compounds proved to be selective for the (peripheral) CCK-A receptor, the most potent analogue, 6, having a Ki value of 90 nM. The structure-activity profile of the series of hybrid compounds relates closest to that of the N-acylglutamic acid derived antagonists.

Topics: Animals; Benzodiazepinones; Cholecystokinin; Computer Simulation; Devazepide; Glutamates; Guinea Pigs; Male; Models, Molecular; Proglumide; Rats; Rats, Inbred Strains; Receptors, Cholecystokinin; Structure-Activity Relationship

To test the possibility that endogenous cholecystokinin (CCK) participates in suppression of sham feeding by intraintestinal nutrient infusions, we examined the effect of CCK-receptor antagonists on the suppression of sham feeding by intraintestinally infused oleic acid, maltose or L-phenylalanine (L-Phe). In addition, we monitored amylase activity in the intestinal lumen during some sham feeding experiments and measured plasma CCK in parallel experiments using intestinally infused animals that were not feeding. Suppression of sham feeding by oleic acid or maltose was attenuated by CCK-receptor antagonists, while suppression of sham feeding by L-Phe was not. Oleate infusion increased plasma CCK concentration and luminal amylase activity. Oleate-induced increase in luminal amylase activity was attenuated by a CCK-receptor antagonist. Intraintestinal maltose or L-Phe did not increase plasma CCK concentration or luminal amylase activity, suggesting that they did not release endocrine CCK. These results suggest 1) that endogenous CCK mediates suppression of sham feeding by oleate and maltose but not by L-Phe and 2) that CCK participating in suppression of feeding by intestinal stimuli might not be of endocrine origin.

Topics: Amylases; Animal Nutritional Physiological Phenomena; Animals; Benzodiazepinones; Catheterization; Cholecystokinin; Devazepide; Duodenum; Eating; Intestines; Male; Maltose; Oleic Acid; Oleic Acids; Phenylalanine; Proglumide; Rats; Rats, Inbred Strains; Receptors, Cholecystokinin; Satiety Response; Sincalide; Stomach

1. Interactions between cholecystokinin octapeptide (CCK-8) and CCKA-receptor antagonists derived from benzodiazepines (devazepide) and glutamic acid (lorglumide and loxiglumide) have been examined in an improved bioassay using the guinea-pig, isolated, gall bladder preparation. 2. The presence of CCKB-receptors in the assay was provisionally-ruled out on the basis of the low potency of pentagastrin in the assay. By applying analyses of both agonism and antagonism, pentagastrin was shown to behave as a partial agonist at the CCKA-receptor. 3. Devazepide, lorglumide and loxiglumide behaved as simple competitive antagonists of CCKA-receptors and pKB values of 9.98, 7.59 and 7.07 were estimated, respectively. 4. Application of a combined dose-ratio analysis to the interactions between CCK-8 and combinations of devazepide/lorglumide and devazepide/loxiglumide indicated that these molecules behave as syntopic, competitive, antagonists at the CCKA-receptor. 5. We conclude that the guinea-pig gall bladder assay contains a homogeneous population of CCKA-receptors and offer an explanation for the differences between our results and those obtained recently by Maubach et al. (1991) which were taken as preliminary evidence for CCKA-receptor heterogeneity.

Topics: Analysis of Variance; Animals; Benzodiazepinones; Binding, Competitive; Biological Assay; Cholecystokinin; Devazepide; Dose-Response Relationship, Drug; Gallbladder; Guinea Pigs; Muscle, Smooth; Pentagastrin; Proglumide; Receptors, Cholecystokinin; Sincalide

The cholecystokinin octapeptide (CCK8)-derived synthetic peptides Boc-Tyr(SO3H)-Nle-Gly-DTrp-Nle-Asp-O-CH2-CH2-C6H5 (JMV179) and Boc-Tyr(SO3H)-Nle-Gly-DTrp-Nle-Asp-NH-CH2-CH2-C6H5 (JMV167) are antagonists of peripheral cholecystokinin (CCK) receptors in vitro. In the present study, antagonist activity of these peptides was studied on rat pancreatic secretion in vivo, and compared to those of other peptidic molecules and to the non-peptidic antagonists L364718, D-, L-, DL-lorglumide, and proglumide. The decreasing order of antagonist potencies on amylase release in vitro was L364718 greater than JMV179 greater than lorglumide greater than JMV167 greater than proglumide; JMV179 was 25 times less potent than L364718 and 300 times more potent than JMV167. The decreasing order of antagonist potencies on protein output in pancreatic juice in vivo was L364718 greater than JMV167 greater than JMV179 greater than lorglumide greater than proglumide; JMV167 was two times more potent than JMV179 and only 8 times less potent than L364718. Increased potency of JMV167, relative to JMV179 under in vivo conditions, is probably due to the slower rate of catabolism of the phenylethylamide group, relative to the phenylethylester group, since the metabolite issued from hydrolysis of the ester bond was totally inactive. This study shows that it is possible to obtain peptidic CCK antagonists, which are active and potent in vivo, and provides a quantitative measurement of potency changes occurring in vivo for several peptidic and non-peptidic antagonists.

Topics: Amino Acid Sequence; Amylases; Animals; Benzodiazepinones; Devazepide; Male; Molecular Sequence Data; Pancreas; Pancreatic Juice; Proglumide; Rats; Rats, Inbred Strains; Receptors, Cholecystokinin; Sincalide

In this investigation we evaluated the effect of two new cholecystokinin (CCK) antagonists, CR 1409 and L364,718, on gallbladder emptying in the opossum. Gallbladder emptying was elicited by both exogenous and endogenous CCK. The three test challenges were 1) intravenous infusion of CCK octapeptide (OP) (10 ng.kg-1.min-1), 2) feeding, and 3) intraduodenal infusion of Isocal (0.4 ml/min), a fat-containing nutrient. During control conditions each test challenge elicited approximately 60% gallbladder emptying within 30 min and 70% emptying by 60 min. At given doses both CR 1409 and L364,718 substantially antagonized or abolished the gallbladder emptying elicited by each of the test challenges. The antagonism for postprandial gallbladder emptying was diminished between 30 and 50 min compared with that for CCK-OP infusion and intraduodenal infusion of Isocal. Unexpectedly, the gallbladder emptying induced by infusion of motilin (5 micrograms.kg-1.h-1) was antagonized by either CR 1409 or L364,718. In anesthetized animals, gallbladder contraction was induced by a variety of agonists, such as bethanechol, histamine phosphate, 5-hydroxytryptamine, and phenylephrine. In this later model CR 1409 and L364,718 functioned solely as selective antagonists. We conclude that for the opossum gallbladder 1) the CCK antagonists CR 1409 and L364,718 antagonize or abolish gallbladder emptying induced by exogenous or endogenous CCK; 2) the pattern of CCK antagonism after feeding suggests that the early phase of postprandial gallbladder emptying is mediated by a mechanism other than endogenous CCK, whereas late postprandial emptying is mediated by release of endogenous CCK; and 3) CR 1409 and L364,718 are not totally specific antagonists for gallbladder CCK receptors alone but also antagonize gallbladder contraction induced by motilin.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Benzodiazepinones; Cholecystokinin; Devazepide; Female; Gallbladder; Kinetics; Male; Opossums; Proglumide; Sincalide

1. Three recently described non-peptide cholecystokinin (CCK) antagonists (devazepide, lorglumide, loxiglumide) have been studied for their antagonism of the contraction to cholecystokinin-octapeptide (CCK-OP) in human alimentary muscle and guinea-pig intestine. 2. Each antagonist caused a concentration-dependent inhibition of the contraction induced by CCK-OP, regardless of regional and species differences. 3. The potencies of each drug, estimated by use of an adaptation of the Cheng & Prusoff equation, were similar in the different regions of human alimentary tract (weighted mean apparent pKB, +/- s.e. mean: devazepide, 5.76 +/- 0.08, n = 20; lorglumide, 5.82 +/- 0.04, n = 25; loxiglumide, 5.87 +/- 0.07, n = 24). 4. In contrast, the potencies differed markedly in the guinea-pig ileum. Apparent pKB values obtained by the same method as with human tissues were, mean +/- s.e.mean: devazepide, 10.61 +/- 0.61; lorglumide, 7.43 +/- 0.20; loxiglumide, 6.67 +/- 0.12. pKB values obtained from classical competition experiments were: devazepide, 10.09 +/- 0.09; lorglumide 7.70 +/- 0.12; loxiglumide 6.08 +/- 0.22. 5. The CCK receptors in human gut muscle from different regions seem to be similar, but there appear to be species differences.

Topics: Animals; Benzodiazepinones; Cholecystokinin; Devazepide; Digestive System; Digestive System Physiological Phenomena; Female; Guinea Pigs; Humans; Ileum; In Vitro Techniques; Male; Muscle Contraction; Proglumide; Receptors, Cholecystokinin; Sincalide

Mechanisms of neural (vagal and cholinergic) and hormonal [cholecystokinin (CCK)] control of pancreatic exocrine secretion were studied in basal interdigestive conditions and after stimulation by an intraduodenal meal in rats equipped with a semichronic pancreatic fistula. Bile was recirculated into the duodenum, and a solution of trypsin and electrolytes was continuously infused. Pancreatic secretion was compared in control experiments, after vagotomy, and after venous infusion of cholinergic and CCK antagonists. Basal pancreatic secretion was decreased by atropine, pirenzepine, and hexamethonium and to a lesser extent by vagotomy (protein output decreased more than fluid and HCO3- outputs). The CCK antagonists L364,718 and lorglumide had no effect on basal interdigestive pancreatic secretion. Small doses of atropine (8 and 25 micrograms.kg-1.h-1) did not modify the cumulated pancreatic response to the meal, whereas larger doses (75 and 225 micrograms.kg-1.h-1) increased it by 40-85%, according to the variables. Pirenzepine and hexamethonium did not modify the pancreatic response. Vagotomy had no effect on fluid and HCO3- responses and tended to increase protein response. L364,718 and lorglumide completely inhibited the protein response and decreased the fluid and HCO3- responses by 75 and 40%, respectively. L364,718 also suppressed the increased pancreatic response induced by atropine. This work confirms the prominent role of neural cholinergic mechanisms in the control of basal interdigestive pancreatic secretion in rats. In contrast, the pancreatic protein response to an intraduodenal meal depends on CCK, whereas fluid and HCO3- responses also depend on other hormonal factors. Our results suggest that a muscarinic (probably M3) mechanism can decrease the postprandial CCK release independently of the pancreatic feedback control by trypsin.

Topics: Animals; Atropine; Benzodiazepinones; Cholecystokinin; Devazepide; Digestion; Duodenum; Eating; Hexamethonium; Hexamethonium Compounds; Kinetics; Male; Muscle, Smooth; Pancreas; Pirenzepine; Proglumide; Rats; Rats, Inbred Strains; Reference Values; Vagotomy

It has been reported that proglumide and L-364,718 potentiate opioid-induced antinociception. However, their mode of action in pain modulation is still not understood. To evaluate a possible interaction with opioid receptors, we determined the affinities of the CCK antagonists proglumide, lorglumide, benzotript and L-364,718 on mu, delta and kappa binding sites, using guinea pig brain crude synaptosome preparations. These affinities were compared to that of the central CCK binding site, using rat brain slide-mounted sections. At 100 microM, proglumide competed for 13% and 17% of mu and kappa binding sites, but did not interact with delta and CCK sites. At this concentration, lorglumide reduced mu, delta, kappa and CCK specific binding by 44%, 69%, 35% and 88%, whereas benzotript diminished it by 16%, 13%, 38% and 48%, respectively. L-364,718 did not interact with opioid receptors (assay limit of solubility, 10 microM) but had a high affinity for CCK binding sites (IC50, 126nM). The lack of selectivity of proglumide, lorglumide and benzotript for CCK receptors suggests that their reported ability to potentiate morphine analgesia may be related to an interaction with opioid receptors.

Topics: Animals; Benzamides; Benzodiazepinones; Binding Sites; Binding, Competitive; Brain; Cholecystokinin; Devazepide; Guinea Pigs; Male; Proglumide; Rats; Rats, Inbred Strains; Receptors, Opioid; Receptors, Opioid, delta; Receptors, Opioid, kappa; Receptors, Opioid, mu

The effects of CCK-receptor antagonists such as dibutyryl cyclic GMP (dbcGMP), L-364,718, and CR1409 on COOH-terminal octapeptide of CCK (CCK-8)-stimulated chief cell responses were examined using isolated guinea pig gastric chief cells. L-364,718 and CR1409 inhibited CCK-8-stimulated pepsinogen secretion over the same concentration range as they inhibited CCK-8-stimulated increases in intracellular Ca2+ concentration ([Ca2+]i), respectively. Schild analysis of the CCK dose-response curve indicates that L-364,718 and CR1409 exert their inhibitory effects on CCK-8-stimulated chief cell responses in a competitive manner. By contrast, dbcGMP inhibited not only CCK-8- but also carbachol-stimulated pepsinogen secretion. Furthermore, dbcGMP inhibited CCK-8-stimulated pepsinogen secretion more potently than the increases in [Ca2+]i. These results suggest that L-364,718 and CR1409 act as CCK-receptor antagonists, but dbcGMP has another inhibitory effect on pepsinogen secretion in addition to the effect as a CCK-receptor antagonist in guinea pig gastric chief cells.

Topics: Animals; Benzodiazepinones; Calcium; Cells, Cultured; Cholecystokinin; Devazepide; Dibutyryl Cyclic GMP; Dose-Response Relationship, Drug; Gastric Mucosa; Guinea Pigs; In Vitro Techniques; Male; Pepsinogens; Proglumide; Receptors, Cholecystokinin; Signal Transduction; Sincalide

The present experiments evaluate in vivo effects of recently described cholecystokinin (CCK) receptor antagonists on rat pancreatic secretion. Pancreaticobiliary secretion was studied after bile duct cannulation in anesthetized rats. After two basal 10-min fractions were selected, secretion was stimulated by intravenous caerulein (0.1-30.0 micrograms/kg) or secretin, and collected for seven further 10-min fractions. Peptide antagonists (CR 1409, CR 1392, and CR 1505) and nonpeptide antagonists (asperlicin and L364,718) were given intravenously 10 min before agonists. Increasing doses of antagonists gradually reduced secretion of protein and enzymes stimulated by submaximal and maximal doses of caerulein. The antagonists did not alter nonstimulated or secretin-stimulated secretion, indicating their specificity for the CCK receptor. Except for proglumide and asperlicin, all antagonists were able to abolish caerulein-stimulated pancreatic secretion, as evaluated by the mean integrated 1-h response to a near-maximal dose of caerulein. The caerulein dose-response curve was gradually shifted to the right by increasing doses of CR 1409, indicating competitive-like kinetics. Inhibition of secretion due to supramaximal doses of caerulein, however, could be reversed by doses of CR 1409 smaller than expected from extrapolating truely competitive kinetics from an in vitro situation to the in vivo situation. The rank order of potency of the compounds to antagonize caerulein-stimulated secretion in vivo agreed with their relative potencies to antagonize caerulein-stimulated amylase secretion from pancreatic acini in vitro as well as with their affinity to bind to peripheral CCK receptors in vitro.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Amylases; Animals; Benzodiazepinones; Ceruletide; Cholecystokinin; Chymotrypsinogen; Devazepide; Dose-Response Relationship, Drug; Male; Pancreas; Proglumide; Proteins; Rats; Rats, Inbred Strains; Receptors, Cholecystokinin; Secretin

Previous studies have demonstrated that cholecystokinin (CCK), gastrin, and structurally related peptides can interact with various types of receptors that can be distinguished by their relative affinities for agonists and antagonists. In the present study we examined the effect of gastrin, the COOH-terminal octapeptide of CCK (CCK-8), and the tetrapeptide of CCK (CG-4) on contraction of dispersed gastric smooth muscle cells from guinea pig and tested the ability of various CCK receptor antagonists to affect agonist-induced muscle cell contraction. For purposes of comparison we tested the effect of each antagonist on CCK-stimulated amylase secretion by pancreatic acini from guinea pig. On gastric smooth muscle cells, CCK-8, gastrin, and CG-4 were all full agonists. CCK-8 and gastrin were equipotent and CG-4 was 6,000-fold less potent. Each antagonist caused inhibition of CCK-stimulated contraction with relative potencies (IC50): L364,718 (4 microM) = CBZ-CCK-(27-32)-NH2 (3 microM) greater than proglumide analogue 10 (90 microM). Inhibition by each of the antagonists was competitive in nature, specific for CCK peptides, and each had the same IC50 whether contraction was stimulated by CCK-8, gastrin, or CG-4. Relative potencies (IC50) of the three antagonists for inhibiting CCK-stimulated amylase release from pancreatic acini were L364,718 (3 nM) greater than proglumide analogue 10 (200 nM) greater than CBZ-CCK-(27-32)-NH2 (3 microM). These results demonstrate that gastric smooth muscle cells possess receptors that differ from CCK receptors on pancreatic acini in terms of affinities for both agonists and certain antagonists.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Amylases; Animals; Benzodiazepinones; Cholecystokinin; Devazepide; Gastrins; Guinea Pigs; Male; Muscle Contraction; Muscle, Smooth; Pancreas; Peptide Fragments; Proglumide; Receptors, Cholecystokinin; Sincalide; Stomach; Tetragastrin

We describe here the properties of tert-butyloxycarbonyl-Trp-Leu-Asp-Phe-NHNH2 (A-57696), a C-terminal hydrazide analogue of tert-butyloxycarbonyl-CCK4 (Boc-Trp-Met-Asp-Phe-NH2), at four cholecystokinin (CCK) receptor-bearing tissues, the guinea pig pancreas and gall bladder (Type A), guinea pig cortex (Type B), and NCI-H345 cells, a human small cell lung cancer cell line that expresses CCK-B/gastrin receptors. Using 125I-Bolton-Hunter-cholecystokinin octapeptide (26-33) (125I-Bolton-Hunter-CCK8) as the radioligand, A-57696 was found to be selective for cortical CCK-B receptors (IC50 = 25 nM), compared with pancreatic CCK-A receptors (IC50 = 15 microM). A-57696 behaved as a competitive antagonist in reversing CCK8-stimulated pancreatic amylase secretion and phosphoinositide breakdown. By Schild analysis, its Kd was determined to be 4.7 and 6.8 microM in amylase and phosphoinositide assays, respectively. A-57696 (100 microM) did not elicit gall bladder contraction, and it inhibited contractions induced by CCK8. The Kd of A-57696 at gall bladder CCK-A receptors was 19 microM. In contrast, A-57696 behaved as a partial agonist (80% of maximal CCK8 response) in stimulating calcium mobilization at CCK-B/gastrin receptors on NCI-H345 cells. A-57696 and CCK8 inhibited each other in calcium mobilization experiments utilizing the fluorescent dye Indo-1. Stimulatory actions of CCK8 and A-57696 were reversed by the CCK-B-selective (R)-L-365,260 (100 nM), whereas at the same concentration, the CCK-A-selective (S)-L-365,260 was ineffective. Binding studies using 125I-Bolton-Hunter-CCK8 and 125I-gastrin indicated that binding sites labeled by these two ligands displayed similar affinities for CCK8, desulfated CCK8, gastrin, A-57696, and both enantiomers of L-365,260. A-57696 represents a new class of CCK-A peptide antagonist at guinea pig pancreas a new class of CCK-A peptide antagonist at guinea pig pancreas and gall bladder. Its contrasting functional activities at guinea pig CCK-A and CCK-B/gastrin receptors in a human tumor cell demonstrate that, in addition to the previously described differences in binding specificity for selective agonists and antagonists, CCK-A receptors and CCK-B/gastrin receptors have different requirements for activation.

Topics: Amino Acid Sequence; Animals; Benzodiazepinones; Calcium; Cholecystokinin; Devazepide; Gastrins; Guinea Pigs; Molecular Sequence Data; Peptide Fragments; Proglumide; Receptors, Cholecystokinin; Tetragastrin

1. Graded doses of bombesin infused I.V. into conscious rats with chronic pancreatic fistulae induced a dose-dependent stimulation of protein secretion, similar to that obtained with caerulein. This stimulation does not appear to be mediated by cholecystokinin (CCK) receptors because peptidergic (CR-1409) and non-peptidergic (L-364718) CCK antagonists failed to affect protein secretion at a dose range which caused almost complete suppression of caerulein-induced pancreatic secretion. 2. Studies in vitro on isolated rat pancreatic acini revealed that caerulein, pentagastrin and bombesin all showed the same efficacy in their ability to stimulate amylase release. In contrast, CCK antagonists competitively inhibited amylase release induced by caerulein and pentagastrin but not by bombesin or urecholine, indicating that the latter two agents act directly on acinar cells via receptors which are separate from those involved in stimulation induced by caerulein and pentagastrin. 3. DNA synthesis, measured by the incorporation of [3H]thymidine into DNA, was significantly stimulated by caerulein, soybean trypsin inhibitor (FOY 305), pentagastrin and by bombesin in a dose-dependent manner. CCK receptor antagonists prevented stimulation of DNA synthesis induced by caerulein, FOY 305 and pentagastrin but not by bombesin. 4. This study indicates that bombesin strongly stimulates pancreatic enzyme secretion, with an efficacy similar to that of caerulein, and also exerts a potent growth-promoting action on the pancreas, both effects appearing to be mediated by mechanisms independent of the CCK receptors.

Topics: Animals; Benzodiazepinones; Bombesin; Ceruletide; Cholecystokinin; Devazepide; DNA; Esters; Gabexate; Glutamine; Guanidines; Pancreas; Pentagastrin; Proglumide; Protease Inhibitors; Proteins; Rats; Receptors, Cholecystokinin

Cholecystokinin (CCK) receptor antagonists may be valuable tools for investigating the physiological role of CCK in islet function. In this study, the effects of the three different CCK receptor antagonists, proglumide, CR 1409 and L-364,718, on basal and stimulated insulin and glucagon secretion were investigated in vivo in the mouse. Each of the CCK antagonists was injected intravenously, either alone or together with one of the secretagogues CCK-8 (5.3 nmol kg-1), carbachol (0.16 mumol kg-1) or glucose (2.8 mmol kg-1). At a low dose level, proglumide (28 mumol kg-1) inhibited selectively CCK-8-induced insulin and glucagon secretion. However, at a higher dose level (280 mumol kg-1), proglumide inhibited also carbachol- and glucose-induced insulin secretion. Furthermore, proglumide elevated basal plasma levels of both glucagon and glucose. CR 1409 inhibited CCK-8-induced insulin secretion at a high (21 mumol kg-1) but not at a low (0.21 mumol kg-1) dose level. In contrast, CCK-8-induced glucagon secretion was not affected by CR 1409. L-364,718 (2.4 mumol kg-1) inhibited both CCK-8-induced insulin and glucagon secretion. In contrast, L-364,718 did not affect basal plasma levels of insulin, glucagon or glucose or those levels after stimulation with carbachol or glucose. We conclude that, of these three CCK antagonists, L-364,718 is the most specific CCK receptor antagonist for studies of both insulin and glucagon secretion in the mouse.

Topics: Animals; Benzodiazepinones; Blood Glucose; Devazepide; Female; Glucagon; Glutamine; Insulin; Insulin Secretion; Islets of Langerhans; Mice; Mice, Inbred Strains; Proglumide; Receptors, Cholecystokinin

Topics: Benzodiazepines; Benzodiazepinones; Chemical Phenomena; Chemistry; Cholecystokinin; Devazepide; Drug Design; Glutamine; Molecular Conformation; Proglumide; Receptors, Cholecystokinin; Stereoisomerism; Structure-Activity Relationship

Peptidal (CR-1409) and nonpeptidal (L-364,718) cholecystokinin (CCK) receptor antagonists were used to determine the possible involvement of CCK in the fasted and fed intestinal motility patterns and the related alterations in pancreatic secretion. Dogs were implanted with electrodes along the small bowel and with chronic pancreatic fistulas. In fasted dogs, the typical migrating motor complex (MMC) cycles and accompanying fluctuations in pancreatic secretion were recorded. Neither of the CCK antagonists affected these motor and secretory components of the MMC. Feeding interrupted the MMC and increased spike activity at all levels of the small bowel, and this was accompanied by a significant increase in pancreatic secretion and in plasma hormone [gastrin, CCK, and pancreatic polypeptide (PP)] levels. Both CCK antagonists significantly reduced the postprandial spike activity but failed to restore the fasted pattern. Exogenous gastrin and CCK, as well as bombesin, induced fedlike motility patterns accompanied by marked pancreatic protein secretion. These effects were completely reversed to the fasted patterns during intravenous infusion of CCK antagonists. In contrast, cholinergic stimulation (bethanechol) induced a fedlike pattern that was more resistant to CCK antagonists. We conclude that CCK does not play a major role in the fasted motility pattern and related fluctuations in pancreatic secretion but may be partly involved (by itself and by released PP) in the induction of the fed motility pattern and the postprandial stimulation of the exocrine pancreas.

Topics: Animals; Benzodiazepinones; Bethanechol Compounds; Bicarbonates; Bombesin; Cholecystokinin; Devazepide; Dogs; Eating; Gastrins; Gastrointestinal Motility; Glutamine; Pancreatic Juice; Proglumide; Proteins; Reference Values

A new simple mouse assay for the in vivo evaluation of CCK antagonists which is based upon visual determination of the gastric emptying of a charcoal meal is described. CCK-8 (24 micrograms/kg s.c.) but not various other peptide and nonpeptide agents effectively inhibited gastric emptying in this test system. The effect of CCK-8 was antagonized by established peripheral CCK antagonists but not representative agents of various other pharmacological classes. The rank order of potency of the CCK antagonists were: L-364,718 (ED50 = 0.01 mg/kg, i.v.; 0.04 mg/kg, p.o.) greater than Compound 16 (ED50 = 1.5 mg/kg, i.v.; 2.0 mg/kg p.o.) greater than asperlicin (ED50 = 14.8 mg/kg i.v.) greater than proglumide (ED50 = 184 mg/kg i.v.; 890 mg/kg, p.o.). Duration of action studies based upon ED50 values determined at various time intervals after oral administration showed that L-364,718 and proglumide are considerably longer acting than Compound 16. Asperlicin (ED50 greater than 300 mg/kg, p.o.) was ineffective as a CCK antagonist when administered orally. These data provide the first direct comparisons of the in vivo potencies of current CCK antagonists and demonstrate the utility of a new simple mouse assay for the in vivo characterization of peripheral CCK antagonists.

Topics: Administration, Oral; Animals; Benzodiazepinones; Binding, Competitive; Cholecystokinin; Devazepide; Dose-Response Relationship, Drug; Female; Gastric Emptying; Mice; Proglumide; Sincalide; Time Factors