fr-173657 and icatibant

Kinins are proinflammatory peptides that mediate a variety of pathophysiological responses. These actions occur through stimulation of two pharmacologically distinct receptor subtypes B1 and B2. In both human and animal airways, the majority of kinin-induced effects including bronchoconstriction, increases in vascular permeability and mucus secretion and cholinergic and sensory nerve stimulation appear to be bradykinin B2-receptor mediated. Peptidic and non-peptidic receptor antagonists have been developed as potential therapeutic agents. These antagonists are effective in blocking kinin-induced effects in a variety of animal models and in some instances, have been used effectively in animal models of allergic airway disease to alleviate allergen-induced pathophysiological airway responses. This review summarizes relevant studies supporting the evidence that bradykinin B2 receptor antagonism and/or upstream inhibition of tissue kallikrein will be beneficial in the treatment of inflammatory airway diseases.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Asthma; Bradykinin; Bradykinin B2 Receptor Antagonists; Disease Models, Animal; Humans; Quinolines; Receptor, Bradykinin B2; Respiratory System; Tissue Kallikreins

Activation of the proteinase-activated receptor-2 (PAR-2) induces scratching behaviour in mice. Here, we have investigated the role of kinin B(1) and B(2) receptors in the pruritogenic response elicited by activators of PAR-2.. Scratching was induced by an intradermal (i.d.) injection of trypsin or the selective PAR-2 activating peptide SLIGRL-NH(2) at the back of the mouse neck. The animals were observed for 40 min and their scratching response was quantified.. I.d. injection of trypsin or SLIGRL-NH(2) evoked a scratching behaviour, dependent on PAR-2 activation. Mice genetically deficient in kinin B(1) or B(2) receptors exhibited reduced scratching behaviour after i.d. injection of trypsin or SLIGRL-NH(2). Treatment (i.p.) with the non-peptide B(1) or B(2)receptor antagonists SSR240612 and FR173657, respectively, prevented the scratching behaviour caused by trypsin or SLIGRL-NH(2). Nonetheless, only treatment i.p. with the peptide B(2)receptor antagonist, Hoe 140, but not the B(1)receptor antagonist (DALBK), inhibited the pruritogenic response to trypsin. Hoe 140 was also effective against SLIGRL-NH(2)-induced scratching behaviour when injected by i.d. or intrathecal (i.t.) routes. Also, the response to SLIGRL-NH(2) was inhibited by i.t. (but not by i.d.) treatment with DALBK. Conversely, neither Hoe 140 nor DALBK were able to inhibit SLIGRL-NH(2)-induced scratching behaviour when given intracerebroventricularly (i.c.v.).. The present results demonstrated that kinins acting on both B(1) and B(2) receptors played a crucial role in controlling the pruriceptive signalling triggered by PAR-2 activation in mice.

Topics: Animals; Antipruritics; Behavior, Animal; Bradykinin; Bradykinin B1 Receptor Antagonists; Bradykinin B2 Receptor Antagonists; Dioxoles; Disease Models, Animal; Dose-Response Relationship, Drug; Injections, Intradermal; Injections, Intraperitoneal; Injections, Intraventricular; Injections, Spinal; Mice; Mice, Inbred C57BL; Mice, Knockout; Oligopeptides; Pain Threshold; Pruritus; Quinolines; Receptor, Bradykinin B1; Receptor, Bradykinin B2; Receptor, PAR-2; Sulfonamides; Trypsin

This study analyzed bradykinin (BK)-evoked contractile responses in the mouse colon under normal and inflammatory conditions. BK and the preferential B(2) receptor agonists Hyp(3)-BK, Lys-BK, Met-Lys-BK and Tyr(8)-BK produced a marked and concentration-related contraction of the normal mouse colon, whereas the selective B(1) receptor agonist des-Arg(9)-BK had no effect. BK-induced contraction was concentration-dependently antagonized (in a non-competitive manner) by both B(2) receptor antagonists Hoe 140 and FR173657, but not the B(1) receptor antagonist des-Arg(9)-[Leu(8)]-BK. Analysis of the possible mechanisms implicated in the contractile responses of BK in the mouse colon revealed the involvement of the neural release of acetylcholine, the activation of L- and N-type voltage-gated calcium channels, and the release of neuropeptides, prostanoids and leukotrienes. The contraction induced by BK was markedly increased in preparations obtained from TNBS-treated mice. The up-regulation of B(2) receptors following the induction of colitis was confirmed with binding studies using [(3)H]-BK, which revealed a marked increase in B(2) receptor densities, without alterations of affinity. We provide convincing evidence on the relevance of B(2) receptors in the mouse colon under normal conditions, as well as under an inflammatory profile of colitis. Selective B(2) receptor antagonists might well represent rational therapeutic options for treating inflammatory bowel diseases.

Topics: Acetylcholine; Animals; Bradykinin; Bradykinin B2 Receptor Antagonists; Calcium Channels, L-Type; Calcium Channels, N-Type; Colitis; Colon; Dose-Response Relationship, Drug; Kallidin; Leukotrienes; Male; Mice; Muscle Contraction; Neuropeptides; Prostaglandins; Quinolines; Receptor, Bradykinin B2; Trinitrobenzenesulfonic Acid

Bradykinin is well known to have a biphasic action to contract and relax gastrointestinal tissue. However, no studies have investigated the potential action of bradykinin to affect the peristaltic reflex. In the present study, serosally applied bradykinin (1-1000 nM) and the bradykinin B2 receptor agonist, kallidin (1-1000 nM), had inhibitory actions and increased the pressure threshold for peristalsis (maximum changes seen at 1000 nM were approximately 60 Pa), as did morphine (IC50=22.3+/-4.8 nM; maximum increase in the pressure threshold was approximately 130 Pa). Conversely, the B1 kinin receptor agonist, [des-Arg9]-bradykinin (1-1000 nM), had no effect (P>0.05). Two potent B2 receptor antagonists, FR173657 (1 and 100 nM) and icatibant (10 nM), significantly antagonized the inhibitory action of serosally applied bradykinin on peristalsis (P<0.01), whilst the B1 receptor antagonist, Lys-[des-Arg9, Leu8]-bradykinin (100 nM) was inactive (P>0.05). In comparison, 5-hydroxytryptamine (1-1000 nM) facilitated peristalsis (EC50=37.7+/-23.0 nM; maximum reduction of the pressure threshold for peristalsis was approximately 76 Pa), as did FR173657 at 100 nM (reducing the pressure threshold for peristalsis by approximately 15 Pa; P<0.05) but icatibant at 10 nM was inactive (P>0.05). The results indicate that bradykinin B2 receptors mediate an inhibition of peristalsis in the guinea pig isolated ileum.

Topics: Animals; Bradykinin; Bradykinin B2 Receptor Antagonists; Guinea Pigs; Ileum; In Vitro Techniques; Kallidin; Male; Morphine; Muscle, Smooth; Peristalsis; Pressure; Quinolines; Receptor, Bradykinin B2; Reflex; Serotonin

The pharmacological characterization of the novel nonpeptide antagonist for the B2 receptor, namely MEN16132 (4-(S)-Amino-5-(4-{4-[2,4-dichloro-3-(2,4-dimethyl-8-quinolyloxymethyl)phenylsulfonamido]-tetrahydro-2H-4-pyranylcarbonyl}piperazino)-5-oxopentyl](trimethyl)ammonium chloride hydrochloride) is presented. The affinity of MEN16132 for the bradykinin B2 receptor has been investigated by means of competition studies at [3H]bradykinin binding to membranes prepared from Chinese Hamster Ovary (CHO) cells expressing the human bradykinin B2 receptor (pKi 10.5), human lung fibroblasts (pKi 10.5), guinea pig airways (pKi 10.0), guinea pig ileum longitudinal smooth muscle (pKi 10.2), or guinea pig cultured colonic myocytes (pKi 10.3). In all assays MEN16132 was as potent as the peptide antagonist Icatibant, and from 3- to 100-fold more potent than the reference nonpeptide antagonists FR173657 or LF16-0687. The selectivity for the bradykinin B2 receptor was checked at the human bradykinin B1 receptor (pKi<5), and at a panel of 26 different receptors and channels. The antagonist potency was measured in functional assays, i.e., in blocking the bradykinin induced inositolphosphates (IP) accumulation at the human (CHO: pKB 10.3) and guinea pig (colonic myocytes: pKB 10.3) B2 receptor, or in antagonizing the bradykinin induced contractile responses in human (detrusor smooth muscle: pKB 9.9) and guinea pig (ileum longitudinal smooth muscle: pKB 10.1) tissues. In both functional assay types MEN16132 exerted a different antagonist pattern, i.e., surmountable at the human and insurmountable at the guinea pig bradykinin B2 receptors. Moreover, the receptor determinants important for the high affinity interaction of MEN16132 with the human bradykinin B2 receptor were investigated by means of radioligand binding studies performed at 24 point-mutated receptors. The results obtained revealed that residues in transmembrane segment 2 (W86A), 3 (I110A), 6 (W256A), and 7 (Y295A, Y295F but not much Y295W), were crucial for the high affinity of MEN16132. In conclusion, MEN16132 is a new, potent, and selective nonpeptide bradykinin B2 receptor antagonist.

Topics: Animals; Binding, Competitive; Bradykinin; Bradykinin B2 Receptor Antagonists; Cells, Cultured; CHO Cells; Cricetinae; Cricetulus; Dose-Response Relationship, Drug; Guinea Pigs; Humans; In Vitro Techniques; Inositol Phosphates; Middle Aged; Muscle Contraction; Muscle, Smooth; Myocytes, Smooth Muscle; Ornithine; Point Mutation; Quinolines; Receptor, Bradykinin B2; Sulfonamides; Transfection

This study was designed to investigate the mechanisms by which bradykinin induces contraction of the pig iris sphincter muscle in vitro. Addition of bradykinin, Lys-bradykinin and Met-Lys-bradykinin to the pig iris sphincter resulted in a graded contraction with a mean EC(50s) of 21, 11 and 5 nM, respectively. The bradykinin B(1) receptor agonist des-Arg(9)-bradykinin only caused a slight contraction, measured 6 h after the tissue was set up. The B(2) receptor antagonists FR 173657 ((E)-3-(6-acetamido-3-pyridyl)-N [N-2-4-dichloro-3-[(2-methyl-8-quinolinyl) oxymethyl] phenyl]-N-methylamino-carbonyl-ethyl] acrylamide) and Hoe 140 (D-Arg(0)-[Hyp(3), Thi(5), D-Tic(7), Oic(8)]-bradykinin produced a graded shift to the right associated with marked inhibition of the bradykinin-induced contraction. Atropine, guanethidine or tetrodotoxin significantly reduced the bradykinin-induced contraction. Dazoxiben, an inhibitor of thromboxane A(2), and MK-571 (3-(3-(2-(7-chloro-2-quinolinyl) ethenyl) phenyl ((3-dimethyl amino-3oxo-propyl) thio) methyl) propanoic acid, a leukotriene D(4) receptor-selective antagonist, also caused inhibition of the bradykinin-mediated contraction. Cyclooxygenase-1 and -2 inhibitors, indomethacin, ibuprofen, valeryl salicylate and NS 398 (N-[2-(cyclohexyloxy)-4-nitrophenyl]methanosulfonamide) all significantly inhibited the bradykinin-mediated contraction without affecting the carbachol-induced contraction of the pig iris sphincter. Taken together, these results indicate that the bradykinin-mediated contraction of the pig iris sphincter muscle seems to be mediated primarily by the activation of the B(2) receptor release of acetylcholine, noradrenaline and both cyclooxygenase-1 and -2 metabolites besides the release of leukotriene D(4) and tromboxane A(2) from the arachidonic acid pathway.

Topics: Animals; Atropine; Bradykinin; Bradykinin Receptor Antagonists; Cyclooxygenase Inhibitors; Dose-Response Relationship, Drug; Enzyme Inhibitors; Guanethidine; Ibuprofen; Imidazoles; In Vitro Techniques; Indomethacin; Iris; Kallidin; Muscle Contraction; Muscle, Smooth; Nitrobenzenes; Propionates; Quinolines; Salicylates; Sulfonamides; Swine; Tetrodotoxin; Thromboxane-A Synthase

1. The involvement of bradykinin (BK) B(2) receptor in acute pancreatitis induced by pancreaticobiliary duct ligation was investigated in rats. 2. The activities of amylase and lipase in the serum, the water content of the pancreas, and vacuolization of the acinar cells were significantly increased 2 h after obstruction of the duct in Sprague-Dawley rats. 3. Elevated serum amylase activity, increased pancreatic oedema, and damage of the pancreatic tissue were significantly less marked in plasma kininogen-deficient, B/N-Katholiek rats than in the normal strain, B/N-Kitasato rats 2 h after the ligation. 4. Obstruction of the pancreaticobiliary duct augmented the level of (1-5)-BK (Arg(1)-Pro(2)-Pro(3)-Gly(4)-Phe(5)), a stable BK metabolite, in the blood from 73.0+/-21.7 pg ml(-1) at 0 h to 149.8+/-38.0 pg ml(-1) at 2 h after the induction of pancreatitis in SD rats. 5. Administration of a BK B(2) receptor antagonist, FR173657 (100 mg kg(-1), p.o.) or Hoe140 (100 nmol kg(-1), s.c.), reduced the elevation of amylase and lipase activities in the serum and of pancreatic water content in a dose-dependent manner. The effective attenuation of oedema formation and vacuolization by the antagonists was also confirmed light-microscopically. In contrast, treatment with gabexate mesilate or indomethacin did not cause significant suppression of the pancreatitis. 6. These findings suggest a possible involvement of kinin B(2) receptor in the present pancreatitis model. Furthermore, they point to the potential usefulness of the B(2) receptor in clinical acute pancreatitis.

Topics: Acute Disease; Amylases; Animals; Anti-Inflammatory Agents, Non-Steroidal; Bile Ducts; Bradykinin; Bradykinin Receptor Antagonists; Dose-Response Relationship, Drug; Edema; Kininogens; Lipase; Male; Pancreas; Pancreatic Ducts; Pancreatitis; Peptide Fragments; Quinolines; Rats; Rats, Inbred Strains; Rats, Sprague-Dawley; Receptor, Bradykinin B2; Water

We have compared the in vivo activity of the bradykinin B(2) receptor peptide antagonists MEN 11270 and Icatibant versus the nonpeptide antagonist FR 173657, after intravenous (i.v.) and intratracheal (i.t.) administration, on the bradykinin (BK)-induced bronchoconstriction and hypotension in anesthetized guinea pigs. We have also assessed the affinity of these antagonists for B(2) receptors in guinea pig lung membranes by radioligand binding and the metabolic stability of peptide antagonists in guinea pig plasma and tissue homogenates. The i.v. administration of MEN 11270, Icatibant, or FR 173657 induced a dose-dependent (10-100 nmol/kg) inhibition of both hypotension and bronchoconstriction induced by bradykinin (10 nmol/kg i.v.). The inhibitory effect of MEN 11270 and Icatibant was comparable both in terms of potency and time course, whereas FR 173657 was less potent and shorter acting. After i.t. administration MEN 11270 and Icatibant (10-100 nmol/kg) dose dependently inhibited both bronchoconstriction and hypotension, whereas FR 173657 (10-100 nmol/kg) reduced bronchoconstriction without affecting hypotension. The antibronchoconstrictor effect of MEN 11270 was more prolonged than that of Icatibant and FR 173657, whereas no differences were found between the peptide antagonists in inhibiting hypotension. These findings indicated that, in vivo, the peptide antagonists are more potent and longer lasting than FR 173657 acting on bradykinin B(2) receptors in guinea pig airways and in the vascular system. The greater efficacy of the antagonists in blocking airway compared with vascular B(2) receptors after topical administration suggests that they can block airway B(2) receptors with little systemic effects.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Blood Pressure; Bradykinin; Bradykinin Receptor Antagonists; Bronchoconstriction; Cell Membrane; Disease Models, Animal; Drug Interactions; Drug Stability; Guinea Pigs; Hypotension; Infusions, Intravenous; Lung; Male; Oligopeptides; Peptides, Cyclic; Quinolines; Receptor, Bradykinin B2; Tritium

The effect of three selective bradykinin B(2) receptor antagonists, MEN11270 (H-DArg-Arg-Pro-Hyp-Gly-Thi-c(Dab-DTic-Oic-Arg)c(7gamma-1 0alpha)), Icatibant (H-DArg-Arg-Pro-Hyp-Gly-Thi-Ser-DTic-Oic-Arg-OH), and FR173567 ((E)-3-(6-acetamido-3-pyridyl)-N-[N-[2, 4-dichloro-3-[(2-methyl-8-quinolinyl) oxymethyl] phenyl]-N-methylaminocarbonylmethyl]acrylamide) was evaluated in the human and rat urinary bladder in vitro and in vivo in anaesthetized rats. Bradykinin evoked a concentration-dependent contraction of human (pD(2)=7.2) and rat (pD(2)=7.7) detrusor muscle strips. In human preparations, all the antagonists tested produced a rightward-shift in the concentration-response curve for bradykinin. Schild plot analysis yielded pK(B) values of 8.4, 8.4 and 8.6 for MEN11270, Icatibant, and FR173567, respectively. In the rat preparations the three antagonists (at 100 nM concentration), produced a shift to the right which gave apparent pA(2) values of 8. 2, 8.0 and 8.1 for MEN11270, Icatibant, and FR173567, respectively. In anaesthetized rats, both MEN11270 and Icatibant (1-10 nmol/kg i.v. ) dose dependently reduced the bradykinin (100 nmol/kg i.v.)-induced urinary bladder contraction, their effect being prompt and long-lasting. In contrast, FR173567 (100 nmol/kg i.v.) produced a partial and short-lasting inhibition of bradykinin-induced bladder contractions. The present findings indicate that all the antagonists tested recognize with similar potencies the bradykinin B(2) receptors expressed in the detrusor muscle of both humans and rats. MEN11270 and Icatibant possess a higher potency and longer duration of action in vivo than FR173657, suggesting that the activity of this non-peptide antagonist in vivo is hampered by factors unrelated to its affinity for bradykinin B(2) receptors.

Topics: Aged; Anesthesia, Intravenous; Anesthetics, Intravenous; Animals; Bradykinin; Bradykinin Receptor Antagonists; Humans; In Vitro Techniques; Male; Middle Aged; Muscle Contraction; Muscle, Smooth; Oligopeptides; Peptides, Cyclic; Quinolines; Rats; Rats, Wistar; Receptor, Bradykinin B2; Urethane; Urinary Bladder

To investigate the molecular basis for the specificity of ligand recognition in human kinin B(1) (B(1)R) and B(2) (B(2)R) receptors, we constructed a series of chimeric receptors by progressively replacing, from the N to the C terminus, the human B(2)R domains by their B(1) counterparts. The chimeric construct possessing the C-terminal tail and the transmembrane domain VII (TM VII) of the B(2)R (construct 6) displayed 7- and 20- fold decreased affinities for the B(1) agonist [(3)H]desArg(10)-kallidin (desArg(10)-KD) and the B(1) antagonist [(3)H]desArg(10)-[Leu(9)]-KD respectively, as compared with the wild-type B(1)R. Moreover, the substitution of the B(1) TM VII by its B(2) homologue TM increased the affinity for the pseudopeptide antagonists, Hoe140 and NPC 567. High affinity for desArg(10)-KD binding was fully regained when the B(2) residue Thr(287) was replaced in construct 6 by the corresponding B(1) Leu(294) residue. When the B(2) residue Tyr(295) was exchanged with the corresponding B(1) Phe(302), high affinity binding for both agonist and antagonist was recovered. Moreover, the L294T and F302Y mutant B(1)R exhibited 69- and 6.5-fold increases, respectively, in their affinities for the B(2) receptor antagonist, Hoe140. Therefore we proposed that Leu(294) and Phe(302) residues, which may not be directly involved in the binding of B(1)R ligands and, hence, their Thr(287) and Tyr(295) B(2) counterparts, are localized in a receptor region, which plays a pivotal role in the binding selectivity of the peptide or pseudopeptide kinin ligands.

Topics: Amino Acid Sequence; Animals; Binding Sites; Bradykinin; Bradykinin Receptor Antagonists; CHO Cells; Cricetinae; Humans; Inositol Phosphates; Kallidin; Molecular Sequence Data; Mutation; Peptides; Protein Binding; Quinolines; Receptor, Bradykinin B1; Receptor, Bradykinin B2; Receptors, Bradykinin; Recombinant Fusion Proteins; Tetrahydroisoquinolines; Transfection

We have compared the pharmacology of different antagonists, Icatibant (H-DArg-Arg-Pro-Hyp-Gly-Thi-Ser-DTic-Oic-Arg-OH), MEN 11270 (H-DArg-Arg-Pro-Hyp-Gly-Thi-c(Dab-DTic-Oic-Arg)c(7 gamma-10 alpha)), and FR173657 ((E)-3-(6-acetamido-3-pyridyl)-N-[N-[2, 4-dichloro-3-[(2-methyl-8-quinolinyl)oxymethyl]phenyl]-N-methyl aminocarbonylmethyl]acrylamide) at bradykinin B2 receptors expressed in the guinea-pig ileum by using bradykinin and the non-peptide FR190997 ((8-[2,6-dichloro-3-[N-[(E)-4-(N-methylcarbamoyl)cinnamidoacety l]-N -methylamino]benzyloxy]-2-methyl-4-(2-pyridylmethoxy)quinoline) as agonists. In organ bath experiments, Icatibant and FR173657 exerted a non-competitive antagonism (pKB 9.5 and 9.2, respectively) of the contractile response to bradykinin, whereas MEN 11270 showed competitive antagonism (pKB 8.3, slope -0.90). The profile of action and apparent affinities of the three antagonists did not change if contact time was prolonged. The inhibition by the three antagonists of the contractile response to bradykinin was differently reverted by washout (MEN 11270 <30 min, Icatibant <60 min, FR173657 >60 min). The non-peptide ligand FR190997 acted as partial agonist if applied cumulatively to the bath (pD2 8.06, Emax 43% of maximal contractility), but as a full agonist when a maximally effective concentration was added (Emax 83%). FR173657 produced non-competitive antagonism of the response to FR190997 with apparent affinity similar to that measured toward bradykinin. On the contrary, Icatibant and MEN 11270 (300 nM both) competitively antagonized the contractile activity exerted by FR190997 with lower apparent pA2 value (6.9 and 7.2, respectively). In radioligand binding experiments, MEN 11270 and Icatibant displaced the [3H]bradykinin binding with pKi of 10.2 and 10.5 (Hill slope not different from unity), respectively. The non-peptide ligands displaced the [3H]bradykinin binding with similar affinity, their pKi being 8.7 and 8.6 for FR173657 and FR190997, respectively (both Hill slopes <1). The present study indicates the difference in the antagonism type (competitive vs. non-competitive) by Icatibant, MEN 11270, and FR173657, as mainly ascribable to their different reversibility from the bradykinin B2 receptor, and affected by the kinetic of the response induced by the different agonists. Results are discussed in view of a different interaction of peptide and non-peptide agonist at the receptor.

Topics: Animals; Binding, Competitive; Bradykinin; Bradykinin Receptor Antagonists; Dose-Response Relationship, Drug; Guinea Pigs; Ileum; In Vitro Techniques; Male; Membranes; Muscle Contraction; Muscle, Smooth; Oligopeptides; Peptides, Cyclic; Quinolines; Receptor, Bradykinin B2; Receptors, Bradykinin

This study examined the mitogenic effects of bradykinin (BK, Arg-Pro-Pro-Gly-Phe-Ser-Pro-Phe-Arg), the peptide bradykinin B(2) receptor antagonist Hoe 140 (D-Arg(0)[Hyp(3)-Thi(6)-D-Tic(7)-Oic(8)]BK, and the orally active, nonpeptide B(2) receptor antagonist FR 173657 ((E)-3-(6-acetamido-3-pyridyl)-N-[N-2-4-dichloro-3-[(2-methyl-8-quino linyl) oxymethyl]phenyl]-N-methylaminocarbonyl-methyl]acrylamide) in three different human tumour cell lines: the small cell lung carcinoma (SCLC) cell line H-69, the breast carcinoma cell line EFM-192A, and the colon carcinoma cell line SW-480. In these cell lines activation of mitogen-activated protein kinase (MAPK) is involved in BK-induced stimulation of cell proliferation and may be mediated by both G(q) proteins (SW-480) and G(i) proteins (EFM-192A; H-69). In these cells BK as well as Hoe 140 increased the rate of DNA synthesis measured with the [(3)H]-thymidine uptake assay. Hoe 140 did neither antagonize nor potentiate the effect of BK. FR 173657 did not stimulate [(3)H]-thymidine incorporation but clearly antagonized the mitogenic effects of BK as well as Hoe 140. In H-69 cells, FR 173657 induced a decrease in the basal rate of DNA synthesis. In all three cell lines BK and Hoe 140 stimulated the activity of MAPK. Their effect on MAPK activity was completely abolished by FR 173657 which itself did not increase the activity of MAPK. In H-69 cells, the basal activity of MAPK was slightly inhibited by FR 173657. In the cell lines SW-480 and H-69 both BK and Hoe 140 but not FR 173657 stimulated phosphatidylinositol hydrolysis. In H-69 cells, FR 173657 decreased basal inositol phosphate formation. Our results show that in certain tumour cell lines the classical peptide B(2) receptor antagonist, Hoe 140, may act as mitogenic B(2) receptor agonist whereas the nonpeptide B(2) receptor antagonist, FR 173657, does not. In H-69 cells FR 173657 was found to exhibit properties of an inverse agonist.

Topics: Bradykinin; Bradykinin Receptor Antagonists; DNA; Dose-Response Relationship, Drug; Enzyme Activation; Enzyme Inhibitors; Flavonoids; Humans; Inositol Phosphates; Mitogen-Activated Protein Kinases; Mitogens; Quinolines; Receptor, Bradykinin B2; Receptors, Bradykinin; Signal Transduction; Tumor Cells, Cultured

We investigated the pharmacological profile of MEN 11270, or H-D-Arg-Arg-Pro-Hyp-Gly-Thi-c(Dab-DTic-Oic-Arg)c(7gamma-10 alpha), a conformationally constrained derivative of the B2 kinin receptor antagonist Icatibant. MEN 11270 bound with high-affinity to the B2 kinin receptor constitutively expressed by WI38 human fibroblasts, inhibiting 3H-bradykinin (BK) with a pKi value of 10.3 +/- 0.08 (n = 5). The rank order of affinity of several peptide and nonpeptide antagonists was also assessed: Icatibant (pKi = 10.6) approximately MEN 11270 (pKi = 10.3) approximately B9430 (pKi = 10.0) > B9858 (pKi = 8.0) > FR173657 (pKi = 7.6) > WIN64338 (pKi = 7.2) > Lys-[des-Arg9, Leu8]-BK (pKi < 6) > [des-Arg9,Leu8]-BK (pKi < 5). MEN 11270 showed a low affinity in inhibiting 3H-Lys-[des-Arg9]-BK binding at the human B1 kinin receptor constitutively expressed by the same cells (pKi 6.0 +/- 0.33; n = 3). MEN 11270 showed no binding affinity (pIC50 < 5.5) at 29 different receptors and ion channels. In the human umbilical vein contraction assay, MEN 11270, shifted the concentration-response curve to BK to the right in a concentration-dependent manner (pA2 8.14 +/- 0.22, n = 7). The Schild plot was linear (slope 0.95 +/- 0.11), consistent with a competitive antagonism. In the same bioassay, MEN 11270 (10 microM) did not affect the concentration-response curve to the B1 agonist Lys-[des-Arg9]-BK nor the contractile responses elicited by noradrenaline or serotonin. These findings indicate MEN 11270 as an antagonist at the human B2 kinin receptor, with potency and selectivity comparable to those of the linear peptide antagonist, supporting the hypothesis that a constrained C-terminal beta-turn conformation preserves a high affinity for the interaction of Icatibant with the B2 kinin receptor.

Topics: Adult; Anti-Inflammatory Agents, Non-Steroidal; Binding, Competitive; Biological Assay; Bradykinin; Bradykinin Receptor Antagonists; Cell Line; Cell Membrane; Female; Humans; In Vitro Techniques; Kinetics; Muscle Contraction; Muscle, Smooth, Vascular; Norepinephrine; Oligopeptides; Peptides, Cyclic; Pregnancy; Quinolines; Receptor, Bradykinin B2; Receptors, Bradykinin; Serotonin; Structure-Activity Relationship; Umbilical Veins

1. Bradykinin is suggested to play a role in the pathophysiology of several acute and chronic diseases, including allergic disorders such as asthma. In the present study, we have investigated the importance of bradykinin in mediating allergic inflammation in rats. 2. To this end we have tested the effects of the B2 receptor antagonists Hoe 140, FR173657 or FR172357 on the pleural inflammatory response triggered by intrapleural (i.pl.) injection of allergen (ovalbumin, 12 microg cavity(-1)) in 14 day-actively sensitized Wistar rats. Analysis of the pleural fluid effluent revealed a sequence of mast cell-dependent inflammatory events, including early protein exudation and neutrophilia and late pleural eosinophil influx. 3. Local treatment with Hoe 140 (0.1 and 1 microg cavity(-1)), FR173657 (1 and 10 microg cavity(-1)) or FR172357 (1 and 10 microg cavity(-1)) inhibited dose-dependently allergen-induced mast cell activation with impairment of pleural plasma leakage, neutrophil accumulation and late eosinophil influx. 4. Moreover, the B2 receptor antagonists also dose-dependently inhibited the allergic like inflammatory pleurisy triggered by bradykinin (50 microg cavity(-1)), which is characterized by acute mast cell degranulation, protein leakage and pleural eosinophil infiltration. 5. Taken together, our findings provide substantial evidence to suggest that bradykinin acting on its B2 receptors play a critical role in mediating allergic mast cell-dependent inflammation in rats, and suggest that B2 receptor antagonists may be useful therapeutically to control allergic dysfunction.

Topics: Allergens; Animals; Anti-Allergic Agents; Bradykinin; Bradykinin Receptor Antagonists; Cell Degranulation; Exudates and Transudates; Female; Histamine Release; Leukocytes; Male; Mast Cells; p-Methoxy-N-methylphenethylamine; Platelet Activating Factor; Pleurisy; Proteins; Quinolines; Rats; Receptor, Bradykinin B2

Pharmacologic parameters for a novel non-peptide bradykinin (BK)-B2 receptor agonist, 8-[2,6-dichloro-3-[N-[(E)-4-(N-methylcarbamoylcinnamidoacetyl]-N-+ ++methylano] benzyloxy]-2-methyl-4-(2-pyridylmethoxy)quinoline (FR 190997) (pEC50, ED50 values) and for the antagonist (E)-3-(6-acetamido-3-pyridyl)-[N-[2,4-dichloro-3-[(2-methyl-8-quinolinyl ) oxymethyl] phenyl]-N-methylaminocarbonylmethyl] acrylamide (FR 173657) (pIC50, ID50 values) were measured using conventional contractile B2 receptor bioassays from rabbit, guinea pig and rat tissues and by mean of animal blood pressure models performed on anesthetized animals in the same species. In vitro assays (on the rabbit jugular vein and the guinea pig ileum) demonstrated that both the onset and duration of action of FR 190997 are prolonged compared to BK. These in vitro effects of FR 190997 strongly desensitized upon repeated tissue applications. Similar pEC50 values (7.7) were measured on the rabbit and the guinea pig tissues. In vivo, when injected intraarterially, FR 190997 produced hypotensive responses in rabbits and guinea pigs with ED50 values of 3.7 +/- 0.5 and 8.9 +/- 3.6 nmol/kg, respectively. Both the contractile and the hypotensive effects of FR 190997 were abolished by pretreating tissues (1 microM) or animals (0.1-0.5 micromol/kg) with D-Arg-[Hyp3,Thi5,D-Tic7,Oic8]BK (HOE 140) or FR 173657. FR 173657 (pIC550 approximately 8.40), as well as other known antagonists (e.g., HOE 140, D-Arg-[Hyp3,D-Phe7,Leu8]BK), inhibited the in vitro myotropic effects of BK on the rabbit, guinea pig and rat tissues. FR 173657 also abrogated the in vivo hypotensive responses elicited by BK in the rabbit (ID50 57 +/- 9 nmol/kg), the guinea pig (ID50 215 +/- 56 nmol/kg) and the rat (ID50 187 +/- 50 nmol/kg). The in vivo duration of action of FR 173657 was significantly lower in the rabbit (= 20 min) than in the guinea pig and the rat (> 90 min). It is concluded that the non-peptides FR 190997 and FR 173657 enable efficient activation and antagonism of rabbit and guinea pig B2 receptors. These non-peptide molecules represent a marked progress in medicinal chemistry and may be useful to define the role played by the kallikrein/kinin system in vivo.

Topics: Animals; Blood Pressure; Bradykinin; Bradykinin Receptor Antagonists; Guinea Pigs; In Vitro Techniques; Muscle Contraction; Quinolines; Rabbits; Rats; Rats, Sprague-Dawley; Receptor, Bradykinin B2; Receptors, Bradykinin

A number of biologically active peptides including bradykinin (BK) are known to elicit an unspecific, non-receptor-mediated release of mediators from mast cells. We have investigated whether novel, nonpeptide BK B2 receptor ligands, i.e., the antagonists N-[N-[3-[(3-bromo-2-methylimidazo(1,2-a]pyridin-8-yl)oxymethyl]-2, 4-dichlorophenyl]-N-methylaminocarbonylmethyl]-4-(dimethylamino carbonyl)cinnamylamide hydrochloride (FR167344) and (E)-3-(6-acetamido-3-pyridyl)-N-[N-(2,4-dichloro-3-¿(2-methyl-8-quinolin yl)oxymethyl¿ phenyl]-N-methylaminocarbonylmethyl]acryamide (FR173657), and the agonist 8-[2,6-dichloro-3-[N-[(E)-4-(N-methylcarbamoyl)cinnamidoacetyl+ ++]-N-methylamino] benzyloxy]-2-methyl-4-(2-pyridylmethoxy)quinoline (FR190997), would be devoid of this unspecific action. Paw oedema in anaesthetized rats was observed following subplantar injection of BK, FR190997, the B2 antagonist D-Arg-[Hyp3, Thi5, D-Tic7, Oic8]-BK (icatibant, previously Hoe-140), the B1 agonist des-Arg9-BK (DABK) and the B1 antagonist des-Arg9 [Leu8]-BK (DALBK). The effect of BK was inhibited by systemic pretreatments with icatibant and methysergide in an additive manner, whereas the local effect of icatibant was only sensitive to methysergide. Oedema induced by DABK and DALBK was also attenuated by methysergide. Mepyramine pretreatment was ineffective for all oedema-producing agents. Effects of FR190997 were abolished by pretreatment with icatibant. FR167344 and FR173657 did not induce oedema formation. Depletion of mast cells by compound 48/80 mimicked the effects of methysergide on BK and icatibant and had no effect on FR190997. It is concluded that the novel nonpeptide receptor ligands are devoid of the unspecific mast cell-degranulating action observed with the peptide ligands.

Topics: Animals; Bradykinin; Cell Degranulation; Dose-Response Relationship, Drug; Female; Mast Cells; Pyridines; Quinolines; Rats; Rats, Sprague-Dawley; Receptors, Bradykinin; Serotonin; Skin

A novel non-peptide bradykinin B2-receptor agonist, FR190997 (8-[2,6-dichloro-3-[N-[(E)4-(N-methylcarbamoyl)cinnamidoacetyl+ ++]-N-methylamino]benzyloxy]-2-methyl-4-(2-pyridylmethoxy)quinolin e), induced dose-dependent and longer-lasting swelling than bradykinin in the mouse paw. The swelling, peaking around 30 min, was suppressed dose-dependently by intraperitoneal administration of FR173657, a novel non-peptide B2-receptor antagonist. A known B2-antagonist, Hoe 140, also significantly suppressed this edema. The result indicates that the novel B2-agonist FR190997, being more stable than bradykinin, could induce plasma exudation locally in mice via the B2-receptor as a substitute for bradykinin.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Bradykinin; Bradykinin Receptor Antagonists; Dose-Response Relationship, Drug; Edema; Foot; Hindlimb; Male; Mice; Mice, Inbred ICR; Quinolines; Receptors, Bradykinin

FR 173657, the first effective nonpeptide kinin B2 receptor antagonist, has been tested in four preparations from different species (human, pig, rabbit, and guinea pig). The new compound shows high apparent affinity for the four B2 receptors, with pA2 values ranging from 8.2 to 9.4 FR 173657 is a selective B2 receptor antagonist that does not interact with human, pig, or rabbit B1 receptors. The new compound is extremely specific for the kinin B2 receptors as it does not affect the myotropic effects of norepinephrine, endothelin-1, or 5-hydroxytryptamine in the human umbilical vein; the contractions elicited by substance P and angiotensin II in the rabbit jugular vein or those produced by acetylcholine and histamine in the guinea pig ileum; or the relaxation of the pig coronary artery induced by norepinephrine and substance P. FR 173657 acts as a competitive antagonist over an extended range of concentrations on human and rabbit B2 receptors, whereas on pig and guinea pig receptors, it depresses the maximal effect of bradykinin and thus appears to act as a noncompetitive antagonist.

Topics: Adult; Analysis of Variance; Animals; Blood Vessels; Bradykinin; Bradykinin Receptor Antagonists; Coronary Vessels; Data Interpretation, Statistical; Female; Guinea Pigs; Humans; Ileum; Jugular Veins; Quinolines; Rabbits; Receptor, Bradykinin B2; Receptors, Bradykinin; Sensitivity and Specificity; Species Specificity; Swine; Umbilical Veins

Contractile responses to B1 and B2 receptor agonists have been demonstrated in the mouse stomach; the mouse urinary bladder responds only to B2 receptor agonists. These tissues were used in this study to investigate the antagonistic effect of four B2 receptor antagonists, namely, DArg[Hyp3,DPhe7,Leu8]BK (BK, bradykinin), HOE-140, WIN 64338, and FR-173657 (B2 receptor antagonists), as well as three B1 kinin receptor antagonists; [Leu8]desArg9BK, Lys[Leu8]desArg9BK, and AcLys[D beta Nal7,Ile8]desArg9BK, were investigated. Results shown indicate that DArg[Hyp3,DPhe7,Leu8]BK is a partial agonist, while HOE-140 and FR-173657 are pure antagonists, devoid of direct myotropic effects, and quite selective for the B2 receptor. WIN 64338 was essentially inactive on both B1 and B2 receptors. The myotropic effect of DArg[Hyp3,DPhe7,Leu8]BK is blocked by HOE-140. Similarly, Lys[Leu8]desArg9BK and [Leu8]desArg9BK are B1 receptor partial agonists whose activities are blocked by AcLys[D beta Nal7,Ile8]desArg9BK (code name R 715), a fairly pure B1 receptor antagonist. Both HOE-140 and FR-173657 are long-acting, slowly reversible compounds that exert a noncompetitive type of antagonism, while R 715 is rapidly reversible and, thus, possibly competitive. Data presented in this paper provide a pharmacological characterization of B1 and B2 receptor antagonists in the mouse and underline the positive features of FR-173657 as a potent and selective B2 receptor antagonist, as well as the potency and purity of R 715 as a B1 receptor antagonist in the mouse.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Bradykinin; Bradykinin Receptor Antagonists; In Vitro Techniques; Kinetics; Mice; Mice, Inbred C57BL; Muscle Contraction; Quinolines; Receptor, Bradykinin B1; Receptor, Bradykinin B2; Receptors, Bradykinin; Stomach; Urinary Bladder