naphthoquinones and methyl-2-((3-4-dihydro-3-4-dioxo-1-naphthalenyl)amino)benzoate

Allergen-induced airways oedema in actively sensitized rats has been studied earlier by magnetic resonance imaging (MRI). We used MRI to follow the consequences of non-immunological mast cell activation induced by compound 48/80 in the rat lungs in vivo.. Male naïve rats were scanned by MRI prior to and at several time points following intratracheal administration of the mast cell secretagogue, compound 48/80. The effects of a range of drugs on the response induced by compound 48/80 were studied.. Strong fluid signals were detected by MRI in the lungs at 24 h after compound 48/80, correlating with increased protein concentration and inflammatory cell infiltration in bronchoalveolar lavage, and with perivascular oedema observed histologically. Pharmacological intervention demonstrated that the increase in MRI signal volume induced by compound 48/80 24 h after challenge was blocked by disodium cromoglycate and the glucocorticoid, budesonide. Pretreatment with wortmannin, capsazepine, DNK333 (a dual neurokinin (NK) 1 and NK2 antagonist) or the anti-allergy drug CGS8515, but not indomethacin, resulted in partial inhibition.. Compound 48/80 induced a complex inflammatory reaction which did not solely involve mast cell degranulation but also activation of sensory nerves and was qualitatively similar to allergen challenge. Changes observed by MRI correlated with decreases in protein concentration in BAL fluid. However, the magnitude of the changes detected was greater using MRI. Our results demonstrate that MRI is a sensitive and efficient tool to assess the effects of drugs on lung inflammation.

Topics: Androstadienes; Animals; Anti-Inflammatory Agents; Aza Compounds; Benzamides; Bronchoalveolar Lavage Fluid; Budesonide; Capsaicin; Cell Degranulation; Cromolyn Sodium; Disease Models, Animal; Drug Evaluation, Preclinical; Indomethacin; Lung; Magnetic Resonance Imaging; Male; Mast Cells; Naphthoquinones; ortho-Aminobenzoates; p-Methoxy-N-methylphenethylamine; Proteins; Pulmonary Edema; Rats; Rats, Inbred BN; Respiratory System Agents; Time Factors; Wortmannin

1. Epithelium-dependent effects of bradykinin (BK) were investigated in a coaxial bioassay system which consisted of guinea pig trachea as donor organ and rat anococcygeus muscle as test tissue. 2. BK (10(-9) to 10(-5) M) produced concentration-dependent relaxations on the phenylephrine (3 x 10(-6) M)-precontracted rat anococcygeus muscle mounted alone. Relaxations decreased significantly when muscle was mounted in epithelium-intact trachea. There was also a significant difference between the relaxations obtained in the muscle within epithelium-intact and epithelium-denuded trachea (at 10(-7) to 10(-5) M concentrations). 3. Capsaicin (10(-5) M) pretreatment did not change BK (10(-9) to 10(-5) M)-induced relaxations in each preparation compared with vehicle pretreatment. Indomethacin (10(-6) M) in combination with thiorphan (10(-5) M) and atropine (10(-6) M) did not affect the BK-induced relaxations of the muscle within capsaicin-pretreated epithelium-intact or denuded trachea. 4. CGS 8515 (a specific 5-lipoxygenase inhibitor, 10(-6) M) did not change BK (10(-5) M)-induced relaxation on the muscle alone, and caused an increase of BK-induced relaxation on the muscle within epithelium-intact trachea compared with that obtained without CGS 8515. 5. Results showed that epithelial or nonepithelial factors were capable of modulating the responsiveness of rat anococcygeus muscle to BK. The decreased relaxation by BK in anococcygeus muscle did not occur by the release of cyclooxygenase products or tachykinins from tracheal epithelium, but it may have occurred by the contractile action of lipoxygenase product secreted by nonepithelial sources. In addition, BK might stimulate the secretion of an epithelium-derived inhibitory factor from the trachea.

Topics: Anal Canal; Animals; Biological Assay; Bradykinin; Capsaicin; Dose-Response Relationship, Drug; Epithelium; Guinea Pigs; Lipoxygenase Inhibitors; Male; Muscle Contraction; Muscle Relaxation; Naphthoquinones; ortho-Aminobenzoates; Rats; Trachea

Interleukin-6 (IL-6) is a cytokine involved in the terminal differentiation of B-cells, T-cell activation, and secretion of hepatic acute phase proteins. The production of IL-6 is regulated by many factors, including IL-1 and lipopolysaccharide (LPS). Because IL-6 may be an important contributor to the effects of LPS in inflammation and septic shock, we investigated the ability of LPS to induce IL-6 release from peritoneal macrophages (m phi) in vitro. M phi were isolated from male Long-Evans rats, and cultured in 96-well tissue culture plates at 1 x 10(5) cells/well in serum-free RPMI-1640 medium. Following a 2-hr attachment period, the cells were rinsed twice to remove the nonadherent cells. LPS (0.006-100 ng/ml) stimulated IL-6 release by six- to 12-fold during a 4 hr incubation. In contrast, IL-1 beta (0.006-100 ng/ml) had no effect. Because cyclooxygenase metabolites of arachidonic acid are increased by LPS, we determined the effects of indomethacin (a cyclooxygenase inhibitor) and CGS8515 (a 5-lipoxygenase inhibitor) on LPS-induced IL-6 release. Neither indomethacin (10 microM) nor CGS8515 (2.5 microM) had any effect on basal or LPS-induced IL-6 release. Very low concentrations of LPS (0.01-1,000 pg/ml) stimulated IL-6 by two- to threefold. Pertussis toxin (10 ng/ml), which inactivates Gi protein, had no effect on LPS-induced IL-6 release from mø. Thromboxane B2 (TXB2) concentrations were also elevated with as little as 0.1 pg/ml LPS; however, pertussis toxin inhibited LPS-stimulated TXB2 release.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Antigens, CD; Antigens, Differentiation, Myelomonocytic; In Vitro Techniques; Indomethacin; Interleukin-1; Interleukin-6; Lipopolysaccharide Receptors; Lipopolysaccharides; Macrophages, Peritoneal; Male; Naphthoquinones; ortho-Aminobenzoates; Pertussis Toxin; Rats; Signal Transduction; Thromboxane B2; Virulence Factors, Bordetella

We evaluated the effect of tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 alpha (IL-1 alpha) on pig cardiopulmonary function by intravenously infusing each cytokine individually or in combination (0.5 microgram/kg from 0 to 0.5 h + 5 ng.kg-1 x min-1 from 0.5 to 6 h for each cytokine). The role of eicosanoids in mediating the TNF-alpha + IL-1 alpha-induced cardiopulmonary dysfunction was also investigated by pretreating cytokine-infused pigs with CGS 8515 (5-lipoxygenase inhibitor) or indomethacin (cyclooxygenase inhibitor). Coinfusion of TNF-alpha with IL-1 alpha caused additive increases (P < 0.05) in total peripheral resistance and plasma concentrations of 6-keto-prostaglandin F1 alpha (PGF1 alpha). The increases in mean pulmonary arterial pressure (Ppa), pulmonary vascular resistance (PVR), alveolar-arterial O2 gradient (AaDO2), alveolar dead space-to-tidal volume ratio (VD/VT), and plasma concentrations of thromboxane B2 were either additive or synergistic. CGS 8515 blocked the TNF-alpha + IL-1 alpha-induced increases (P < 0.05) in mean aortic pressure, total peripheral resistance (4-6 h), VD/VT (5-6 h), and, at 6 h, attenuated the increases in Ppa, PVR, and AaDO2. Indomethacin blocked or attenuated the cytokine-induced increases (P < 0.05) in Ppa, PVR, AaDO2, VD/VT, and plasma concentrations of thromboxane B2 and 6-keto-PGF1 alpha. The 1-to 2-h systemic hypotension, caused by TNF-alpha + IL-1 alpha, was not abrogated by either indomethacin or CGS 8515. The cytokines did not alter plasma concentrations of leukotriene B4 or 5-hydroxyeicosatetraenoic acid. We conclude that coinfusion of TNF-alpha with IL-1 alpha induces physiological responses that are additive or synergistic and that cyclooxygenase and 5-lipoxygenase products (other than leukotriene B4 and 5-hydroxyeicosatetraenoic acid) importantly mediate cardiopulmonary dysfunction in pigs infused with TNF-alpha + IL-1 alpha.

Topics: 6-Ketoprostaglandin F1 alpha; Albumins; Animals; Arachidonic Acids; Bronchoalveolar Lavage Fluid; Chromatography, High Pressure Liquid; Cyclooxygenase Inhibitors; Cytokines; Dinoprost; Drug Synergism; Eicosanoids; Heart; Heart Diseases; Hydroxyeicosatetraenoic Acids; Indomethacin; Injections, Intravenous; Interleukin-1; Leukotriene B4; Lipoxygenase Inhibitors; Lung; Lung Diseases; Naphthoquinones; ortho-Aminobenzoates; Swine; Thromboxane B2; Tumor Necrosis Factor-alpha; Vascular Resistance

We hypothesized that 5-lipoxygenase and cyclooxygenase products might be mediators of cardiopulmonary and systemic vascular effects induced by a 4 h continuous infusion of platelet-activating factor (PAF, 10 ng/kg/min) in anesthetized pigs. Indomethacin (cyclooxygenase inhibitor) potentiated and CGS 8515 (5-lipoxygenase inhibitor) attenuated PAF-induced increases in total peripheral resistance (TPR) from 2.5 to 4 h. However, the 5-lipoxygenase inhibitor failed to modify pulmonary vasoconstriction and hypertension caused by PAF. Except for a delay in onset (approximately 44 s) and rate of development of pulmonary hypertension during the initial 10 min of PAF infusion, the pulmonary hemodynamic changes were also not attenuated by indomethacin. On the other hand, at 4 h, the PAF-induced pulmonary hypertension and systemic vasoconstriction were completely or partially reversed, respectively, by WEB 2086 (PAF receptor antagonist). The PAF-induced increases in plasma thromboxane B2 (TXB2) were blocked by indomethacin but not by CGS 8515, and at 4 h the 5-lipoxygenase inhibitor potentiated the levels of TXB2 in pigs treated with PAF. The plasma concentrations of 6-keto-PGF1 alpha and leukotriene B4 (LTB4) were not modified by PAF or CGS 8515 + PAF. We conclude that PAF-induced increases in TPR (2.5-4 h) are potentiated by indomethacin and are dependent on 5-lipoxygenase products other than LTB4. Although the early pulmonary vascular response (< 10 min) to PAF is dependent on cyclooxygenase products, the sustained response (after 10 min) cannot be explained by either 5-lipoxygenase or cyclooxygenase products but may be mediated directly by PAF receptors.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Azepines; Blood; Calcimycin; Chromatography, High Pressure Liquid; Cyclooxygenase Inhibitors; Hemodynamics; Hypertension, Pulmonary; In Vitro Techniques; Indomethacin; Infusions, Intra-Arterial; Leukotriene B4; Lipoxygenase Inhibitors; Naphthoquinones; ortho-Aminobenzoates; Platelet Activating Factor; Swine; Thromboxane B2; Triazoles

Lipoxygenase (LO) activity has been implicated in the process by which activated human monocytes oxidize normal human low density lipoprotein (LDL) and render it toxic to target cells. Here we examined the role of 5-LO in activated monocyte-mediated LDL modification. Five putative inhibitors of 5-LO (A63162, CGS8515, PF5901, RG6866, and MK886) were used to determine if they prevented activated monocytes from oxidizing LDL. Only RG6866, A63162, and CGS8515 inhibited monocyte-mediated LDL oxidation. Nonspecific effects of these drugs on LDL oxidation by activated monocytes were examined. RG6866 and A63162 were both found to be general antioxidants at their effective concentrations. CGS8515 was toxic at its effective concentration. A63162, CGS8515, and RG6866 also inhibited 15-LO activity in vitro. MK886 and PF5901 did not exhibit the nonspecific effects above and did not inhibit monocyte-mediated LDL oxidation, whereas both MK886 and PF5901 inhibited production of 5-LO metabolites by activated monocytes at concentrations that had no effect on LDL oxidation by the activated monocytes. Since neither of these agents inhibited LDL oxidation, we conclude that 5-LO is not involved in human monocyte oxidation of LDL. The possibility that a cellular 12- or 15-LO is involved in human monocyte-mediated LDL oxidation remains to be evaluated.

Topics: Acetamides; Arachidonate 15-Lipoxygenase; Arachidonate 5-Lipoxygenase; Benzyl Compounds; Humans; Hydroxamic Acids; In Vitro Techniques; Lipoproteins, LDL; Lipoxygenase Inhibitors; Monocytes; Naphthoquinones; ortho-Aminobenzoates; Oxidation-Reduction; Phenyl Ethers

Naphthoquinones are known to inhibit 5-lipoxygenase. In particular, CGS 8515 (methyl 2-[(3,4-dihydro-3,4-dioxo-1-naphthalenyl)amino]benzoate) has been studied in detail. However this potent and selective 5-lipoxygenase inhibitor has a short duration of action and poor bioavailability. To improve the duration of action we have prepared a series of carbon substituted naphthoquinones. Several members of this series have demonstrated potent in vitro inhibition of 5-LO (IC50's less than 10(-6) M) and at doses of 1 mg/kg iv completely inhibited LTB4 production measured in ex vivo A23187-stimulated blood from dogs. The duration of action measured by the ex vivo assay was improved up to threefold over CGS 8515.

Topics: Animals; Biological Availability; Calcimycin; Dogs; Female; Guinea Pigs; Half-Life; In Vitro Techniques; Leukotriene B4; Lipoxygenase Inhibitors; Male; N-Formylmethionine Leucyl-Phenylalanine; Naphthoquinones; ortho-Aminobenzoates; Radioimmunoassay

Topics: Animals; Chromatography, High Pressure Liquid; Dogs; Electrochemistry; Lipoxygenase Inhibitors; Naphthoquinones; ortho-Aminobenzoates

The o-naphthoquinone derivative, CGS 8515 (I), is a potent inhibitor (IC50, 0.1 microM) of 5-lipoxygenase, but its therapeutic potential is compromised by a short plasma half-life (22 min) and extremely poor oral bioavailability (less than 2%). Poor biopharmaceutical properties of CGS 8515 were attributed to poor aqueous solubility and rapid in vivo hydrolysis of its methyl ester function to an inactive metabolite (IC50, 100 microM). An active amide analogue (II) was synthesized to prevent rapid hydrolysis. While analogue II appeared to be stable in vivo, its plasma half-life was also short (10 min), possibly because of rapid tissue distribution rather than metabolic elimination. Therefore, three potent analogues with increased aqueous solubilities were synthesized and compared with respect to their pharmacokinetic properties. The analogue with the highest aqueous solubility (V) demonstrated a plasma concentration vs time profile with the largest area under the curve (AUC) and the smallest distribution (alpha) phase of all the analogues studied. The percentage AUC of the terminal phase (beta) for three analogs paralleled their aqueous solubilities. The oral bioavailability of V was improved to 27%, compared to 2% for the parent compound, CGS 8515.

Topics: Administration, Oral; Animals; Dogs; Dose-Response Relationship, Drug; Enzyme Inhibitors; Humans; Lipoxygenase Inhibitors; Liver; Naphthoquinones; ortho-Aminobenzoates; Portacaval Shunt, Surgical; Solubility

Topics: Anaphylaxis; Animals; Azepines; Cyclooxygenase Inhibitors; Guinea Pigs; Heart; In Vitro Techniques; Indomethacin; Leukotrienes; Lipoxygenase Inhibitors; Naphthoquinones; ortho-Aminobenzoates; Platelet Activating Factor; Thromboxane A2; Triazines; Triazoles

1. CGS 8515 selectively inhibited 5-LO (IC50 = 0.1 microM) with negligible effect on CO, 12-LO, 15-LO and TxS at concentrations up to 100 microM. 2. CGS 8515 selectively inhibited A23187-induced formation of 5-LO products in rat and human whole blood with a 20-70 fold separation of effects over the formation of CO products. 3. Ex vivo and in vivo studies with rats showed that CGS 8515, at an oral dose of 2-50 mg/kg, significantly inhibited A23187-induced formation of LTs in whole blood and in the lung. The effect persisted for at least 6 h in the ex vivo blood model. 4. CGS 8515, at oral doses as low as 5 mg/kg, significantly suppressed exudate volume and leukocyte migration in the carrageenan-induced pleurisy and sponge models in the rat.

Topics: Animals; Arachidonate 5-Lipoxygenase; Arachidonate Lipoxygenases; Arachidonic Acids; Calcimycin; Cell Movement; Humans; Kinetics; Leukocytes; Lipoxygenase Inhibitors; Naphthoquinones; ortho-Aminobenzoates; Rats

CGS 8515 inhibited 5-hydroxyeicosatetraenoic acid (5-HETE) and leukotriene B4 synthesis in guinea pig leukocytes (IC50 = 0.1 microM). The compound did not appreciably affect cyclooxygenase (sheep seminal vesicles), 12-lipoxygenase (human platelets), 15-lipoxygenase (human leukocytes) and thromboxane synthetase (human platelets) at concentrations up to 100 microM. CGS 8515 inhibited A23187-induced formation of leukotriene products in whole blood (IC50 values of 0.8 and 4 microM, respectively, for human and rat) and in isolated rat lung (IC50 less than 1 microM) in vitro. The selectivity of the compound as a 5-lipoxygenase inhibitor was confirmed in rat whole blood by the 20-70-fold separation of inhibitory effects on the formation of leukotriene from prostaglandin products. Ex vivo and in vivo studies with rats showed that CGS 8515, at an oral dose of 2-50 mg/kg, significantly inhibited A23187-induced production of leukotrienes in whole blood and in the lung. The effect persisted for at least 6 h in the ex vivo whole blood model. CGS 8515, at oral doses as low as 5 mg/kg, significantly suppressed exudate volume and leukocyte migration in the carrageenan-induced pleurisy and sponge models in the rat. Inhibitory effects of the compound on inflammatory responses and leukotriene production in leukocytes and target organs are important parameters suggestive of its therapeutic potential in asthma, psoriasis and inflammatory conditions.

Topics: Animals; Arachidonate Lipoxygenases; Arachidonic Acid; Arachidonic Acids; Benzoquinones; Biotransformation; Blood Platelets; Calcimycin; Dexamethasone; Guinea Pigs; Humans; Hydroxyeicosatetraenoic Acids; Indomethacin; Leukocytes; Leukotriene B4; Lipoxygenase Inhibitors; Male; Naphthoquinones; ortho-Aminobenzoates; Pleurisy; Quinones; Rats; Rats, Inbred Strains; Sheep

To determine the relative importance of arachidonic acid pathway products on vulnerability to ventricular fibrillation (VF), we examined the effects of synthesis inhibitors and a receptor blocker acting in the cyclooxygenase (C) and lipoxygenase (L) pathways on VF thresholds in a feline model of coronary occlusion. Thresholds for the induction of VF wer measured before and after a 5-minute coronary occlusion in drug-treated animals and control subjects. Animals were treated with BW755c, a dual L and C inhibitor, CGS-8515, and L inhibitor, FPL-55712, a leukotriene receptor blocker, or sulfinpyrazone, a C inhibitor. BW755c, CGS-8515, and FPL-55712 all prevented an otherwise significant fall in VF threshold during coronary occlusion (p less than 0.01) independent of an effect on effective refractory period, heart rate, or blood pressure. In contrast, sulfinpyrazone, the only compound devoid of an effect on the L pathway, did not protect against an occlusion-related fall in VF threshold. BW755c and CGS-8515 inhibited the synthesis of L and C metabolites coincident with their protection against VF (p less than 0.01). We conclude that agents that antagonize the effects of L products protect against enhanced ventricular vulnerability during acute ischemia, whereas C inhibition alone may not afford this protection.

Topics: 4,5-Dihydro-1-(3-(trifluoromethyl)phenyl)-1H-pyrazol-3-amine; Animals; Anti-Inflammatory Agents, Non-Steroidal; Arachidonic Acid; Arachidonic Acids; Cardiac Pacing, Artificial; Cats; Chromones; Coronary Disease; Female; Male; Naphthoquinones; ortho-Aminobenzoates; Pyrazoles; SRS-A; Sulfinpyrazone; Ventricular Fibrillation

1. Ovalbumen (100 micrograms)-induced coronary vasoconstriction and decrease in cardiac developed tension were studied in isolated perfused hearts from sensitized guinea-pigs. Leukotriene-like material released in the cardiac effluent was assayed against synthetic leukotriene C4 (LTC4). 2. LTC4 was released in a time-dependent fashion, and release was enhanced when hearts were challenged in the presence of indomethacin (2.8 microM). The release was maximal at 2-3 min and detectable for as long as 10 min following ovalbumen challenge. Immunoreactive (ir) thromboxane-B2 (TxB2) was also detected in cardiac effluent which had been partially purified using C18 Sep-Paks. 3. CGS 8515 (0.03-1.0 microM), an inhibitor of 5-lipoxygenase, dose-dependently inhibited ovalbumen-induced coronary vasoconstriction and leukotriene-C4 release. CGS 8515 inhibited ovalbumen-induced decreases in cardiac developed tension at 0.3 and 1.0 microM, but did not antagonize coronary vasoconstriction induced by synthetic LTC4. 4. The release of cyclo-oxygenase products following ovalbumen challenge was not inhibited by CGS 8515, but was markedly inhibited by indomethacin (2.8 microM) pretreatment. 5. We conclude that leukotrienes have a major role in guinea-pig cardiac anaphylaxis, and that CGS 8515 has a cardio-protective action. The results obtained in these experiments in vitro show that CGS 8515 is a potent and selective 5-lipoxygenase inhibitor.

Topics: 4,5-Dihydro-1-(3-(trifluoromethyl)phenyl)-1H-pyrazol-3-amine; Anaphylaxis; Animals; Guinea Pigs; Heart; In Vitro Techniques; Lipoxygenase Inhibitors; Male; Naphthoquinones; ortho-Aminobenzoates; Ovalbumin; Perfusion; Prostaglandin-Endoperoxide Synthases; Pyrazoles; SRS-A

The effects of a highly selective 5-lipoxygenase inhibitor, CGS8515 [methyl 2-[(3,4-dihydro-3,4-dioxo-1-naphthalenyl) amino]benzoate], on endotoxic shock sequelae and eicosanoid synthesis by peritoneal macrophages were evaluated in the rat. Pretreatment of peritoneal macrophages in vitro with CGS8515 significantly inhibited the synthesis (P less than .01) of immunoreactive leukotriene C4/leukotriene D4 stimulated by the calcium ionophore (A23187). Inhibition of 5-lipoxygenase produced significant shunting to immunoreactive thromboxane B2 formation (P less than .05). In rats sedated with ketamine.HCl (82.5 mg/kg) and xylazine. HCl (27.5 mg/kg), i.v. injection of Salmonella enteritidis endotoxin (25 mg/kg i.v.) produced significant decreases at 30 min in mean arterial pressure (from 89 +/- 4 to 44 +/- 8 mm Hg, N = 5, P less than .001); in white blood cell count (from 10.8 +/- 0.6 to 6.5 +/- 0.8 x 10(3)/mm3, N = 5, P less than .01); in platelet count (from 687 +/- 66 to 392 +/- 65 x 10(3)/mm3, N = 5, P less than .01); and produced an increase of hematocrit (from 46 +/- 1.2 to 57.4 +/- 1.8%, N = 5, P less than .03). CGS8515 (5 mg/kg i.v. 30 min before endotoxin injection, N = 6) blunted the endotoxin-induced hypotension by 35% (P less than .001), the leukopenia by 24% (P less than .03), the thrombocytopenia by 45% (P less than .006) and the hemoconcentration by 16% (P less than .03), compared to the shocked control rats 30 min after endotoxin injection.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Arachidonate Lipoxygenases; Blood Pressure; Hematocrit; Leukopenia; Lipoxygenase Inhibitors; Male; Naphthoquinones; ortho-Aminobenzoates; Rats; Shock, Septic; Thrombocytopenia; Thromboxane B2