Pharmacological characteristics of Sho-seiryu-to, an antiallergic Kampo medicine without effects on histamine H1 receptors and muscarinic cholinergic system in the brain

The pharmacological characteristics of Sho-seiryu-to, an antiallergic Kampo medicine, were investigated. Forty-eight-hour passive cutaneous anaphylactic (PCA) reaction was significantly inhibited in rats orally administered Sho-seiryu-to (1000 mg/kg). Sho-seiryu-to significantly inhibited increase in vascular permeability induced by histamine. These data confirm previous findings that Sho-seiryu-to has antiallergic activity in animals and suggest that the antagonism of histamine may be an antiallergic mechanism of Sho-seiryu-to. Sho-seiryu-to did not affect locomotor activity or motor coordination in mice. Although ketotifen prolonged sleeping time induced by pentobarbital, Sho-seiryu-to had no such effect. Nor was there any effect on oxotremorine-induced tremor and [3H]-mepyramine binding to histamine H1 receptors in rat brain. Thus, Sho-seiryu-to appears to be useful for treating type I allergy, with relatively few side effects such as sedation and drowsiness due mainly to blockade of histamine H1 and muscarinic receptors in the brain.

An anaphylaxis inhibitory factor present in mouse serum

We have previously described that normal mouse serum inhibits the PCA reaction mediated by IgE. The present study attempts to characterize this PCA inhibitory factor from the biologically active fraction of the serum. The physicochemical properties of this glycoprotein are the following: it is inactivated at 55 degrees C; it has a molecular weight between 182 kD and 240 kD, determined by gel filtration; it shows affinity to concanavalin A and lentil lectin but not to peanut agglutin; it demonstrates affinity to IgE and, apparently, its carbohydrate moiety is not required for its biological activity. Two bands corresponding to 64.5 kD and 48. 1 kD, which are likely to constitute the biologically active molecule, are observed by SDS-PAGE. These properties are different from those found in factors with IgE affinity involved in IgE synthesis.

[Effects of mao-bushi-saishin-to (MBST) on experimental allergic models in rats]

Effects of oral administration of MBST on 48 hr homologous passive cutaneous anaphylaxis (PCA) and allergic rhinitis in rats were examined. Administration of MBST (1,000 mg/kg/day) for 5 consecutive days with the final dosing at 1 day before antigen challenge did not effect on PCA. However, the reaction was significantly inhibited when the drug (1,000 mg/kg) was singly given 1 hr before antigen challenge. The drug (1,000 mg/kg, 1 hr prior to antigen challenge) tended to reduce the dye leakage into nasal cavities by antigen, while it did not affect on the anaphylactic histamine release into the cavities. The component of the chinese plants in the formula inhibiting the dye leakage was found to be Mao. However, l-ephedrine and d-pseudoephedrine, which are contained in Mao in a large amount, did not contribute to the inhibiting effect on dye leakage. These results suggest that MBST may be therapeutically effective for atopic disease including rhinitis, through the mechanism other than the inhibition of histamine release.

[Antigenicity study of iodixanol, a new non-ionic contrast medium]

Antigenic potential of iodixanol, a new non-ionic contrast agent, was evaluated by systemic anaphylaxis (SA) test and homologous passive cutaneous anaphylaxis (Homo-PCA) test using guinea pigs and IgE mediated heterologous PCA (Hetero-PCA) test using rats passively sensitized with mouse sera. SA test was conducted in guinea pigs sensitized with iodixanol at dose levels of 32 or 320 mgI/kg emulsified with Freund's complete adjuvant, followed by challenge with iodixanol (320 mgI/kg). Four- or 24-hr Homo-PCA test was performed with sera from the sensitized animals. Neither positive SA nor Homo-PCA reaction was observed. Hetero-PCA test was performed with the sera from the mice which were sensitized with iodixanol (32 or 320 mgI/kg) with aluminum hydroxide gel. No positive Hetero-PCA reaction was detected in the sera, followed by challenge with iodixanol (320 mgI/kg). Thus, it is concluded that iodixanol possesses no antigenic potential under the present experimental conditions.

[Pharmacological studies on KW-4679, an antiallergic drug. (1): Inhibitory effect on passive cutaneous anaphylaxis (PCA) and experimental asthma in rats and guinea pigs]

The present experiment was carried out to elucidate the antiallergic properties of KW-4679. Oral administration of KW-4679 showed a dose-dependent inhibition on the IgE-mediated 48-hr homologous PCA in rats, with an ID50 value of 0.04 mg/kg. Passive anaphylactic broncho-constriction in guinea pigs mediated by IgE-like homologous antibody against ovalbumin was prevented dose-dependently by treatment with KW-4679 at doses of 0.03-1 mg/kg, p.o. KW-4679 also inhibited the IgE-mediated active anaphylactic bronchoconstriction in rats. In passively sensitized guinea pigs, the inhalation of aerosol antigen decreased the dynamic compliance of the lung and increased the mean pulmonary resistance. Pretreatment with KW-4679 (0.03-1 mg/kg, p.o.) inhibited antigen-induced airway obstructions. Oral administration of KW-4679 significantly protected rats from compound 48/80-induced lethality. These results indicate that KW-4679 might be useful in the treatment of allergic diseases such as asthma.

Passive cutaneous anaphylaxis in diabetic rats

The effect of diabetic condition on heterologous passive cutaneous anaphylaxis (PCA) reaction was studied. In alloxan diabetic rats, PCA reaction was inhibited by 68.2% of control values. The skin hyposensitivity in diabetic rats could not be attributed to a lower quantity of skin mast cells; it is suggested that alterations in the endothelial cells of the microcirculatory blood vessels decrease permeability to biologically active mast cell factors.

[Effect of mao-bushi-saishin-to (MBST), a formula of Chinese medicines, on 48 hr homologous passive cutaneous anaphylaxis in rats]

We studied the effect of oral administration of the extracts from MBST and its component chinese plants, and 1-ephedrine on 48 hr homologous passive cutaneous anaphylaxis (PCA), and histamine- or serotonin-induced skin reaction in rats. Administration (100-1,000 mg/kg) of MBST 1 hr before antigen challenge dose-dependently inhibited PCA. Skin reaction induced by histamine was also inhibited by this formula at 1,000 mg/kg 1 hr prior to the provocation in some degree. The inhibitory component of MBST of PCA was found to be Mao. Further examinations revealed that 1-ephedrine, which is contained in Mao in a large amount, did not substantially inhibit histamine- or serotonin-induced skin reaction. These results indicate that MBST has a significantly inhibitory activity on PCA, to which 1-ephedrine from Mao in the formula almost totally contributes, through the inhibition of chemical mediator release. Since MBST showed some inhibition of histamine-induced skin reaction, on which 1-ephedrine did not affect, it is suggested that some ingredient of MBST responsible for inhibition of PCA may be involved in addition to 1-ephedrine.

Inhibitory effects of methanolic extract from corydalis tuber against types I-IV allergic models

Methanolic extract (CM-ext) from tubers of Corydalis turtschaninovii forma yanhusuo has been screened for activity in experimental models of types I-IV allergy. In type I allergic models, CM-ext at doses of 200, 500 mg/kg, p.o. inhibited 48-h homologous passive cutaneous anaphylaxis (PCA) in rats which is related to IgE, and 4-h heterologous PCA in guinea pigs which is related to IgG. The inhibition of CM-ext on 48-h PCA was also recognized in adrenalectomized rats. CM-ext exhibited the inhibitory effect on formation of IgE antibody in BALB/c mice. In type II allergic model, it was found that CM-ext inhibits reversed cutaneous anaphylaxis (RCA). In type III allergic model, CM-ext showed the inhibitory effect on direct passive arthus reaction (DPAR) in rats. Furthermore, in type IV allergic model, CM-ext had the inhibitory effects on induction phase and effector phase in picryl chloride-induced contact dermatitis (PC-CD). It also showed therapeutic action on PC-CD. These results indicated that CM-ext not only inhibits antibody-mediated allergic reactions but also influences cell-mediated allergic reactions and should be recognized as a potent material for allergic reactions, although the mechanisms and active principles of CM-ext have not yet been completely determined.

Effects of tubercidin and its 5'-O-methyl ether on adenosine receptors and mediator release functions in mast cells

Tubercidin (7-deazaadenosine, Tu) is a highly cytotoxic nucleoside xenobiotic that, as the nucleoside or nucleotide derivatives, closely mimics the actions of adenosine (or its corresponding nucleotides) in a wide variety of biochemical/biological systems. In light of its acceptance in these test systems as an adenosine (Ado) surrogate, it was postulated that the compound might interact with adenosine receptors. To test this hypothesis, a nonphosphorylatable derivative (5'-O-methyl tubercidin, MeTu) was prepared and evaluated in comparison with tubercidin and Ado in a variety of biological systems. In a cell culture assay using Chinese hamster ovary cells, MeTu is approximately one-third as cytotoxic as is Ado and 10(5)-fold less cytotoxic than Tu. Both Tu and MeTu inhibited the antigen-stimulated release of beta-hexosaminidase from mouse bone marrow derived mast cells in vitro, but only Tu was active in the in vivo PCA test. The inhibitory effect of MeTu on mast cell mediator release does not appear to involve interaction with adenosine receptors or to be the result of conversion to Tu per se.

Studies on antiulcer agents. II. Antiulcer properties of N-(1H-tetrazol-5-yl)-2-anilino-5-pyrimidinecarboxamides inhibiting release of histamine from passively sensitized rat peritoneal mast cells

With the aim of applying mast cell-stabilizing agents as antiulcer agents, N-(1H-tetrazol-5-yl)-2-anilino-5-pyrimidinecarboxamides were synthesized, and initially evaluated pharmacologically for activity in the rat passive cutaneous anaphylaxis test by oral administration. The most active compound 6 was proved to inhibit potently the release of histamine from passively sensitized rat peritoneal mast cells in vitro. When compared with other mast cell-stabilizing agents and an antiulcer agent, compound 6 was found to show excellent gastric mucosal protection and gastric antisecretion activities. Furthermore, compound 6 revealed good activity against acidified aspirin ulcer in rats and water-immersion stress ulcer in rats.

Antiallergic constituents from oolong tea stem

The antiallergic constituents of oolong tea stem were examined. The stem extracts inhibited the 48 h homologous passive cutaneous anaphylaxis (PCA) reactions or rats in a dose-dependent manner and showed the same extent of inhibitory activity as ketotifen. All antiallergic constituents from the stem were concentrated into chloroform and ethyl acetate fractions, when extracted by various solvents. These fractions were treated with polyvinylpolypyrrolidone (PVPP), which resulted in the elimination of antiallergic activity in the ethyl acetate fraction, suggesting that one of the antiallergic constituents may be tea catechins. Then, six kinds of catechins, (-)-epigallocatechin gallate (EGCG), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECG), -epicatechin (EC), (+)-catechin (C) and (-)-gallocatechin gallate (GCG), were isolated from the ethyl acetate fraction, and the inhibitory activity of these catechins on histamine release from rat peritoneal mast cells passively sensitized with anti-egg albumin (EA) IgE antibody was investigated. Among these catechins, significant inhibitory activity was observed in all the catechins except for EC. In addition, the inhibitory activity of GCG was greater than that of EGCG, which is well known to be an antiallergic constituent in tea. These results suggest that GCG may be a novel antiallergic constituent among tea catechins, and also the most potent.

Anti-anaphylactic activity of the novel selective histamine H1 receptor antagonist mizolastine in the rodent

The anti-anaphylactic/anti-histamine activity of mizolastine (CAS 108612-45-9, SL 85.0324), a novel histamine H1 receptor antagonist devoid of sedative properties, has been evaluated in the rat, mouse and guinea pig. Mizolastine inhibited the passive cutaneous anaphylactic reduction caused by ovalbumin challenge in the rat (ED50 = 0.7 mg/kg i.v., 1.6 mg/kg p.o.) and effectively protected rats from the lethal shock induced by compound 48/80 (ED50 = 0.07 mg/kg p.o.). Mizolastine protected actively sensitized guinea pigs from anaphylactic mortality, bronchospasm and respiratory difficulties (increase in pulmonary resistance) preceding this event and from morphological modifications at doses from 0.05 mg/kg i.v. The pharmacological activity of mizolastine is linked to a selective blockade of histamine H1 receptors as indicated by the ability of this compound to antagonize rat paw edema induced by the subplantar injection of histamine (ED50 = 0.5 mg/kg p.o.) but not that induced by the injection of serotonin or bradykinin. Mizolastine also antagonized the increase in cutaneous capillary permeability caused by the intradermal injection of histamine (-80% at 0.3 mg/kg p.o.) and compound 48/80 (ED50 = 1.1 mg/kg p.o.) but not that induced by serotonin in the rat. In the guinea pig, mizolastine antagonized i.v. histamine-induced bronchoconstriction (ED50 = 0.03 mg/kg p.o.) and histamine-induced vascular permeability and edema in trachea and bronchi (ED50 < or = 0.05 mg/kg i.v.). Moreover, at higher doses, mizolastine antagonized the bronchospasm caused by systemic injection of platelet-activating factor (PAF) and leukotriene D4 (LTD4) (ED50's = 0.30 and 3.0 mg/kg p.o., respectively). However, mizolastine only weakly antagonized bronchospasm induced by aerosolized PAF (-67% at 50 mg/kg p.o.), failed to antagonize (up to 3 mg/kg i.v.) PAF-induced microvascular permeability of the tracheal mucosa in the guinea pig and was a weak inhibitor of PAF-induced platelet aggregation in the rabbit (IC50 = 74 mumol/l). In addition to antagonizing histamine H1 receptors, mizolastine also inhibits the release of histamine during allergic reactions in tissues. Thus, mizolastine antagonizes the antigen-induced in vivo release of histamine from mast cells in bronchoalveolar lavages of actively sensitized guinea pigs (minimal effective dose 0.3 mg/kg p.o.) and the release of histamine from mast cells in the peritoneal fluid of passively sensitized rats (ED50 = 0.9 mg/kg i.v.). In these various models, mizolastine was more potent than loratadine and terfenadine but less potent than ketotifen. The apparent half-life for the pharmacological actions of mizolastine ranged from 6 to 8 h.(ABSTRACT TRUNCATED AT 400 WORDS)

Immunogenicity of biosynthetic human LysPro insulin compared to native-sequence human and purified porcine insulins in rhesus monkeys immunized over a 6-week period

Development of insulin antibodies in rhesus monkeys was investigated after immunization with 3 forms of insulin in Freund's adjuvant. Insulins examined included: 1. biosynthetic LysPro insulin (LY275585), a new human insulin analog, 2. biosynthetic native-sequence human insulin, and 3. purified porcine insulin. Male monkeys, 4/insulin type, were immunized weekly over a 6-week period with increasing doses of insulin, ranging from 10 to 100 micrograms/monkey. An ELISA assay was used to measure IgG insulin antibodies in sera collected prior to immunization and 5, 10, and 16 days after final immunization. One monkey had detectable pretreatment levels of antibody. This monkey, which had been assigned to the LysPro insulin treatment group, responded to immunization with a peak antibody level of 20 micrograms/ml. IgG insulin antibody responses were not detected in any of the other monkeys. A passive cutaneous anaphylaxis (PCA) assay was used to measure IgE insulin antibodies in sera collected prior to immunization and 10 days after final immunization. No IgE antibodies were detected in any of the monkeys pre- or post-immunization. Considering that 1. an immunological adjuvant was used, 2. eleven of twelve monkeys failed to develop an antibody response, and 3. the IgG insulin antibody level observed in the single responding monkey was low, it was concluded that these insulins have an extremely weak immunogenic potential in rhesus monkeys. It is suggested that immunization of non-human primates with new therapeutic proteins in adjuvant may be a useful primary screen to determine their immunogenic potential.(ABSTRACT TRUNCATED AT 250 WORDS)

Inhibition of plasma extravasation by abruquinone A, a natural isoflavanquinone isolated from Abrus precatorius

Polymyxin B-induced hind-paw edema was suppressed by abruquinone A, an isoflavanquinone isolated from Abrus precatorius, in normal as well in adrenalectomized mice. Unlike dexamethasone, abruquinone A did not increase the liver glycogen content in fasting adrenalectomized mice. The volume of exuded plasma was significantly reduced by abruquinone A in neurogenic inflammation, passive cutaneous anaphylactic reaction and compound 48/80-induced ear edema. Histamine-, serotonin-, bradykinin- and substance P-induced plasma extravasation in ear edema was also suppressed by abruquinone A. Abruquinone A, like isoproterenol, significantly reduced the bradykinin- and substance P-induced plasma extravasation in normal as well as in compound 48/80-pretreated mice. In addition, abruquinone A suppressed the bradykinin- and substance P-induced ear edema to a significantly greater extent than diphenhydramine/methysergide did. In the in vitro experiments, abruquinone A suppressed the compound 48/80-induced histamine and beta-glucuronidase released from isolated rat peritoneal mast cell preparations. These results suggest that the anti-inflammatory effect of abruquinone A is mediated partly via the suppression of the release of chemical mediators from mast cells and partly via the prevention of vascular permeability changes caused by mediators. The glucocorticoid activity and the release of glucocorticoid hormones from the adrenal gland are probably not involved.

Anti-inflammatory effects of a short-acting and a long-acting beta 2-adrenoceptor agonist in guinea pig skin

The pharmacological modulation of the accumulation and function of eosinophils in tissues may have a significant impact in the treatment of allergic diseases such as asthma, atopic dermatitis and rhinitis. In this study, we have investigated the acute anti-inflammatory effects of a short-acting (salbutamol) and a long-acting (salmeterol) beta 2-adrenoceptor agonist on 111In-accumulation and oedema formation in allergic and mediator-induced inflammation in guinea pig skin. Both salbutamol and salmeterol inhibited 111In-eosinophil accumulation induced by platelet-activating factor and in a passive cutaneous anaphylactic reaction when co-injected with the inflammatory stimuli or when given as a 30 min pretreatment. The inhibition was reversed by DL-propranolol, but not D-propranolol. Systemic treatment with salbutamol inhibited 111In-eosinophil accumulation and oedema formation when given as a 15 min, but not as a 3 h, pretreatment. In contrast, salmeterol was effective when given at both times. We conclude that a long duration of action of beta 2-adrenoceptor agonists is not necessary to demonstrate acute anti-inflammatory effects on eosinophil accumulation in guinea pig skin.

Antiallergic activity of alkyl substituted pyrazolo[3, 4-d]pyrimidine (compound 88-765)

Compound 88-765 (4-amino-6-methylthio-1-(2', 2'-diethoxyethyl)-1 H-pyrazolo[3, 4-d]pyrimidine) has shown potent antiallergic activity in experimental models. The compound inhibited the passive cutaneous anaphylaxis (PCA) reaction in rats in dose-dependent manner (5-100 mg/kg, po) by 47 to 87%. In mice it inhibited PCA by 78% at 50 mg/kg, po. It also inhibited mast cell degranulation of normal and passively sensitised rats induced by compound 48/80 and egg albumin, respectively. These effects of Compound 88-765 were comparable with that of disodium cromoglycate (DSCG). The results suggest that compound 88-765 possesses potent antiallergic activity.

Allergic conjunctivitis and uveitis models: reappraisal with some marketed drugs

The purpose of this study was to assess the activity of some marketed products in ocular non-immune and immune type I hypersensitivity reactions, and during intra-ocular type III hypersensitivity. In order to compare these activities, we improved and validated three different models of ocular allergic reaction already known for their ability to reproduce allergic conjunctivitis or uveitis. Allergic conjunctivitis was induced by ocular immediate hypersensitivity after instillation of compound 48/80 in the rat, or an active anaphylaxis reaction with ovalbumin immunisation and challenge in the guinea pig. Uveitis was induced by a reverse passive anaphylaxis reaction using intra-vitreal rabbit anti-bovine IgG anti-serum sensitisation and intravenous bovine gamma-globulin challenge in the rabbit. Clinical scores and blood-tissue permeability indices were studied. Using the same schedule of ocular instillation, the effects of Livostin (levocabastine 0.05%), Almide (lodoxamide 0.1%), Opticrom (sodium cromoglycate 2%), Ocufen (flurbiprofen 0.03%), Acular (ketorolac 0.5%) and 0.3% chlorpheniramine maleate were compared to positive and negative controls. We demonstrated the potent activity of chlorpheniramine maleate 0.3% and Livostin in both allergic conjunctivitis models. Significant activity was also evidenced with Almide, which was only active in the non-immune allergy model, while Opticrom was definitely not active in these models. In the uveitis model, Acular and Ocufen are active and potent drugs, while Livostin and Almide were not active. These results are discussed with respect to the models used and the mediators involved.

Accumulation of granulocytes in the lung and skin of guinea pigs. Inhibition by the anti-H1 antiallergic agent epinastine

The aim of this study was to investigate whether the antiallergic/H1-antagonistic drug epinastine (WAL 801, Alesion, CAS 108929-04-0) inhibited inflammatory granulocyte infiltration in respiratory or dermal tissue. A late-phase bronchial eosinophilia was induced in sensitized and challenged guinea pigs, and a skin chamber technique was developed for assessing leukotriene-B4 (LTB4) induced transdermal chemotaxis in vivo in this species. Oral epinastine as well as the reference compounds beta-methasone and the LTB4-receptor antagonist 7-[3-(4-acetyl-3-methoxy-2-propylphenoxy) propoxy]-3,4-dihydro-8-propyl-2H-1-benzopyran-2-carboxylic acid (ADCA) demonstrated a dose-dependent inhibition of granulocyte accumulation. The rank order of oral activity was epinastine > betamethasone > ADCA for bronchial eosinophilia and betamethasone > epinastine = ADCA for transdermal chemotaxis. These animal studies suggest a non-antihistamine activity of epinastine which may contribute to its clinical efficacy as an antiallergic drug.

Synthesis and antiallergic activity of novel azaazulene derivatives

Various azaazulene derivatives were synthesized and their antiallergic activity was examined. The structure-activity relationship among various derivatives modified by introducing substituents at the 1-,2-, or 3-position of the azaazulene ring was investigated. The inhibitory activities on allergic histamine release of the compounds bearing a 5-tetrazolyl group at the 3-position were more potent than those of the corresponding compounds with other groups (CN, COOH, and CHO). The compounds substituted with amino, azide and carboxymethylamino groups at the 2-position showed strong inhibitory activity. The compounds with various phenylalkyl groups at the 1-position showed a greater activity than those with other substituents. Among the compounds with substituents at the 1-,2-, or 3-position of the azaazulene ring, 1-benzyl-7-isopropyl-3-(5-tetrazolyl)-1-azaazulen-2-one (18f) and 1-(4-fluorobenzyl)-7-isopropyl-3-(5-tetrazolyl)-1-azaazulen- 2-one (19c) had the most potent inhibitory activities on histamine release from mast cells and on passive cutaneous anaphylaxis (PCA) in rats after oral administration (ED50 = 0.56 and 0.58 mg/kg, respectively).

Mast cell recovery following chronic treatment with compound 48/80

Histochemical and functional properties of mast cells (MC) in Brown Norway rats recovering from chronic treatment with the MC secretagogue compound 48/80 were examined. In the skin, treatment for 5 days with compound 48/80 resulted in a marked decrease in MC subpopulations defined by differential alcian blue/safranin staining. Both safranin-positive connective tissue MC and alcian blue staining MC were reduced in number. This was accompanied by significant decreases in skin histamine and rat MC serine protease I contents and a loss of specific IgE-mediated passive cutaneous anaphylaxis (PCA) activity. The PCA reaction did not return to normal before 2 months after stopping treatment and only when the numbers of safranin-positive connective tissue MC and skin histamine content reached pretreatment levels. The subepidermal alcian blue staining MC not eliminated by the compound 48/80 treatment were formalin resistant (unlike alcian blue staining mucosal MC of the intestine) and apparently played no role in the PCA response. MC numbers, histamine levels, and rat MC serine protease I content of the tongue were similarly decreased by compound 48/80. In contrast, mucosal MC of the gut were unaffected by the secretagogue treatment.

Differential effects of the PAF receptor antagonist UK-74,505 on neutrophil and eosinophil accumulation in guinea-pig skin

1. The effect of the dihydropyridine, platelet activating factor (PAF) receptor antagonist, UK-74,505, on leucocyte accumulation and oedema formation in guinea-pig skin was investigated. The inflammatory reactions studied were elicited by exogenous mediators, a passive cutaneous anaphylactic (PCA) reaction and zymosan particles. 2. Leucocyte accumulation and oedema formation were measured as the local accumulation of i.v. administered 111In-labelled neutrophils or eosinophils together with 125I-labelled albumin. UK-74,505 was either administered i.v. or used to pretreat the radiolabelled leucocytes in vitro prior to their last wash and injection into recipient animals. 3. In vitro, UK-74,505 inhibited PAF-induced elevations in cytoplasmic levels of Ca2+ ([Ca2+]i) in fura-2-loaded guinea-pig neutrophils and eosinophils with IC50 values of 10(-9) M and 7 x 10(-9) M respectively. Neutrophils and eosinophils pretreated with 10(-7) M and 10(-6) M UK-74,505 respectively, and maintained at 37 degrees C, were unresponsive to PAF for the 4 h period investigated. 4. In vivo, using 2 h test periods, i.v. UK-74,505 (0.5 and 2.5 mg kg-1) inhibited the accumulation of 111In-neutrophils, 111In-eosinophils and oedema formation induced by intradermal PAF, but had no effect on responses elicited by leukotriene B4 (LTB4) and zymosan-activated plasma (ZAP, used as a source of C5a des Arg). UK-74,505 (2.5 mg kg-1) was also without an effect on response induced by a PCA reaction but significantly suppressed the 111In-eosinophil accumulation following the intradermal administration of zymosan particles. The 111In-neutrophil accumulation induced by zymosan particles was not, however, affected by UK-74,505. 5. In a second series of in vivo experiments, "'In-leucocytes were pretreated in vitro with UK-74,505 prior to their last wash and injection into recipient animals. Radiolabelled neutrophils, and eosinophils were pretreated with 10-7 M and 10-6 M UK-74,505 respectively, concentrations previously shown to block the leucocyte responses to PAF in vitro for up to 4 h. The in vitro pretreatment of the cells with the PAF antagonist, whilst not affecting the responses to intradermally-injected PAF, suppressed the"'In-eosinophil accumulation response induced by zymosan particles.6. The results of this study indicate that PAF is not involved in neutrophil accumulation, eosinophil accumulation and oedema formation induced by LTB4, ZAP and a PCA reaction. Endogenous PAF does, however, appear to have a role in zymosan-induced eosinophil accumulation but not neutrophil accumulation, suggesting the existence of different inflammatory pathways in the induction of neutrophil and eosinophil accumulation in vivo. Furthermore, while leucocyte accumulation induced by exogenous PAF does not appear to involve leucocyte PAF receptors, the mechanism by which endogenous PAF mediates the zymosan-induced eosinophil accumulation appears dependent on the expression of PAF receptors on eosinophils.

Antiallergic effects of ZCR-2060: effect on allergic cutaneous reactions and rhinitis models in mice and rats

The antiallergic action of 2-[2-[4-(diphenylmethyl)-1-piperadinyl] ethoxy] benzoic acid maleate (ZCR-2060) was investigated on allergic cutaneous reactions and nasal vascular permeability in mice and rats. ZCR-2060 markedly inhibited immediate allergic cutaneous reactions, including passive cutaneous anaphylaxis (PCA) in rats and mice; histamine-, compound 48/80- and calcium ionophore A 23187-induced cutaneous reactions in rats; and biphasic skin reactions mediated by monoclonal IgE antibody and epicutaneous challenge with antigen in mice, but did not affect 5-hydroxytryptamine-induced cutaneous reaction in rats. The antigen-induced nasal vascular permeability increase in actively and passively sensitized rats and histamine-induced nasal vascular permeability increase in rats (allergic rhinitis model) were clearly inhibited in a dose-dependent fashion by ZCR-2060. Moreover, ZCR-2060 significantly inhibited antigen-induced anaphylactic histamine release from rat peritoneal mast cells and carrageenin-induced paw edema in rats. These results suggest that ZCR-2060 has antiallergic effects on allergic cutaneous reactions and experimental rhinitis, probably due to histamine H1-receptor blockage and the inhibition of histamine release.

Synthesis and topical antiinflammatory and antiallergic activities of antioxidant o-aminophenol derivatives

In order to develop novel compounds for topical use possessing antiallergic as well as antiinflammatory activities, a series of o-aminophenol derivatives bearing H1-antihistaminic structures were synthesized and their effects were investigated on lipid peroxidation in rat brain homogenates, antiinflammatory effection arachidonic acid- and 12-O-tetradecanoylphorbol-13- acetate-induced mouse ear edema and antiallergic effect on 48-h homologous passive cutaneous anaphylaxis in rats. Furthermore, the effects of these compounds on delayed-type hypersensitivity reaction in mice were examined. Several N-monosubstituted amino-4-methylphenols were found to exert potent inhibitory activities in all of these assays. Of these compounds, 4m was chosen for further development as AD0261.

[Development of bioactive functions in hydrangeae dulcis folium. II. Antiulcer, antiallergy, and cholagoic effects of the extract from hydrangeae dulcis folium]

In order to develop new bioactive functions of Hydrangeae Dulcis Folium, the fermented and dried leaves of Hydrangea macrophylla Seringe var. thunbergii Makino, effects of the methanolic extract from the crude drug on antiucler, antiallergic, cholagoic, and various pharmacological actions were investigated. Consequently, the methanolic extract was found to exhibit potent antiulcer, antiallergic, and cholagoic activities. By monitoring with these activities, it was found that the active constituents were contained in the lipophilic portion of the methanolic extract. Furthermore, the known lipophilic constituents such as phyllodulcin and hydrangenol were found to show little antiulcer and cholagoic activities, while it was also found that they showed antiallergic activity on Schultz-Dale reactions.

Effects of phosphodiesterase isoenzyme inhibitors on cutaneous inflammation in the guinea-pig

1. Inflammation is central to the pathophysiology of asthma. The recent findings that different inflammatory cells may express different phosphodiesterase (PDE) isoenzymes have centered attention on inhibitors of these isoenzymes as new drugs for the treatment of asthma. In this study, we investigated the effect of different PDE isoenzyme inhibitors on the accumulation of 111In-labelled eosinophils and local oedema formation at sites of allergic- and mediator-induced inflammation in guinea-pig skin. 2. Systemic treatment with SK&F 94120, a type III PDE inhibitor, or zaprinast, a type V PDE inhibitor, had no effect on the 111In-eosinophil accumulation and oedema formation induced by i.d. injection of zymosan-activated plasma (ZAP), PAF, histamine or in a passive cutaneous anaphylaxis (PCA) reaction. 3. Systemic treatment with rolipram, a type IV PDE inhibitor, effectively inhibited 111In-eosinophil accumulation induced by ZAP, PAF, histamine and in a PCA reaction. However, oedema formation measured in the same sites was not affected. Systemic administration of higher doses of theophylline produced similar results. In contrast, 111In-neutrophil accumulation induced by ZAP or in a PCA reaction was not altered by systemic treatment with rolipram. 4. Locally-injected rolipram had little effect on 111In-eosinophil accumulation and oedema formation induced by histamine, PAF and in a PCA reaction. 5. These data show that systemic, but not local, treatment with rolipram effectively inhibits allergic- and mediator-induced 111In-eosinophil accumulation but not oedema formation or 111In-neutrophil accumulation. This, taken together with the potent inhibitory effects of PDE type IV inhibitors on eosinophil function in vitro, suggest that this class of drugs may be beneficial in disease states such as asthma where eosinophils are thought to play a major pathophysiological role.

A khellin-like 7,7'-glycerol-bridged bischromone with anti-anaphylactic activity

The synthesis of the title compound 3 is described. Its performance in Passive Cutaneous Anaphylaxis (PCA) testing was evaluated.

Effect of a 5-lipoxygenase inhibitor, ZM 230487, on cutaneous allergic inflammation in the guinea-pig

1. Leukotrienes have potent biological effects in vitro and in vivo and are found in tissue and in biological fluids in various pathological conditions including allergic diseases. Leukotriene B4 (LTB4) is a potent stimulus for eosinophil accumulation and activation and there is much interest in determining its importance in mediating the accumulation of eosinophils at sites of allergic inflammation in vivo. In this study, we investigated the effects of a potent 5-lipoxygenase inhibitor, ZM 230487, on the accumulation of eosinophils and on local oedema formation in cutaneous inflammation in the guinea-pig. 2. The i.d. injection of increasing concentrations of arachidonic acid (AA) led to a dose-dependent accumulation of 111In-eosinophils but oedema formation was only significant at the top dose of AA tested (3 x 10(-8) mol per site). Co-injection of ZM 230487 with AA inhibited 111In-eosinophil accumulation up to 99% but the small oedema response to AA was only partially inhibited. AA-induced oedema formation was only effectively inhibited when a combination of a PAF antagonist, an antihistamine and ZM 230487 was used. 3. Local administration of the cyclo-oxygenase inhibitor, ibuprofen, partially inhibited AA-induced oedema formation suggesting that vasodilator prostaglandins may be released following i.d. injection of AA. AA-induced 111In-eosinophil accumulation was also partially inhibited by ibuprofen. 4. PAF-induced 111In-eosinophil accumulation was partially suppressed by local administration of ZM 230487. In contrast, LTB4-induced 111In-eosinophil accumulation was enhanced by ZM 230487. These data suggest that locally-released leukotrienes may modulate mediator-induced eosinophil accumulation. ZM 230487 had no effect on PAF- or LTB4-induced oedema formation. 5. ZM230487 significantly inhibited the accumulation of 111 In-eosinophils, but did not affect local oedema formation, in a passive cutaneous anaphylaxis (PCA) reaction. However, the PAF antagonist WEB 2086 either alone or in combination with ZM 230487 had no effect on "'In-eosinophil accumulation or oedema formation in the PCA reaction.6. In conclusion, it appears that a product of 5-lipoxygenase, probably LTB4, is important for the accumulation of "'In-eosinophils, but not local oedema formation, in the PCA reaction in guinea-pigskin. These data support a major role for LTB4 in allergic inflammation in the guinea-pig and make this animal (and the PCA model) suitable for studying the effects of inhibitors of leukotriene synthesis or action in vivo.

Antigenicity study of the new cognition-enhancing agent nefiracetam

The potential antigenicity of the new cognition-enhancing agent nefiracetam (N-(2,6-dimethylphenyl)-2-(2-oxo-1-pyrrolidinyl)acetamide, DM-9384, CAS 77191-36-7) was investigated by tests for passive cutaneous anaphylaxis (PCA), systemic anaphylaxis (SA) and skin reaction in mice and guinea pigs. Mice were sensitized with nefiracetam (10-100 micrograms/animal) or nefiracetam-egg albumin (OA) mixture (10 micrograms/animal). No IgE antibodies to nefiracetam were detected in plasmas obtained from nefiracetam and nefiracetam-OA sensitized mice, indicating that nefiracetam has no immunogenicity or antigenicity eliciting potential. Guinea pigs were sensitized with nefiracetam (20-100 or 20 mg/kg) or nefiracetam-OA (2 mg/kg). No antibodies to nefiracetam were detected in the sera obtained from sensitized guinea pigs by PCA. Neither SA nor skin reaction was observed in the sensitized guinea pigs after the injection of challenge. These results suggest that nefiracetam possesses no antigenicity in mice and guinea pigs.

Acute effects of deflazacort and its metabolite 21-desacetyl-deflazacort on allergic reactions

The acute effects of deflazacort (MDL 458, CAS 14484-47-0) and its metabolite, 21-desacetyl-deflazacort, on allergic reactions in animal models were investigated and compared with those of prednisolone. Deflazacort, 21-desacetyl-deflazacort and prednisolone all inhibited 48-h homologous passive cutaneous anaphylaxis in rats, but had no significant effects on active systemic anaphylaxis in mice, on the Schultz-Dale reaction in the isolated guinea-pig trachea or on compound 48/80-induced histamine release in rat peritoneal mast cells. All three agents inhibited reversed cutaneous anaphylaxis in rats and the Arthus reaction in mice. The inhibitory effects of deflazacort on the passive cutaneous anaphylaxis, the reversed cutaneous anaphylaxis and the Arthus reaction were similar to those of 21-desacetyl-deflazacort and were stronger than those of prednisolone. Delayed type hypersensitivity in mice was also inhibited by deflazacort and 21-desacetyl-deflazacort, but prednisolone, at the doses used in the present study, had little effect on this immune response. These findings indicate that while deflazacort and 21-desacetyl-deflazacort have stronger anti-allergic effects than prednisolone, they seem to have little acute effect on mast cell degranulation or on chemical mediators at the receptor site.

Inhibitory effect of norathyriol, a xanthone from Tripterospermum lanceolatum, on cutaneous plasma extravasation

Norathyriol, a xanthone aglycon isolated from Tripterospermum lanceolatum, was demonstrated to reduce the plasma leakage elicited by the passive cutaneous anaphylactic reaction in normal as well as in adrenalectomized mice. Capsaicin pretreatment greatly suppressed the local edema caused by antidromic stimulation of the saphenous nerve. The plasma exudation of neurogenic inflammation was also reduced in mice treated with norathyriol, diphenhydramine and methysergide, but not with indomethacin. Norathyriol, cyproheptadine and diphenhydramine combined with methysergide suppressed the ear edema caused by injection of compound 48/80, bradykinin and substance P into the ear. However, indomethacin did not affect this phlogist-induced edema response. Histamine- and serotonin-induced plasma exudation in ear edema was also reduced by norathyriol. In isolated rat peritoneal mast cell preparations, norathyriol produced a dose-dependent inhibition of histamine and beta-glucuronidase release from mast cells challenged by compound 48/80, bradykinin and substance P. In compound 48/80-pretreated mice, norathyriol at higher concentrations suppressed the bradykinin- and substance P-induced ear edema to a significantly greater extent than diphenhydramine combined with methysergide did. These data indicate that the inhibitory effect of norathyriol on local edema is not due to the release of steroid hormones from the adrenal gland, but is probably partly due to suppression of mast cell degranulation and hence reduce the release of chemical mediators which increase vascular permeability, and partly, at least in higher doses, due to protection of the vasculature from challenge by various mediators.

Preparation and pharmacological activities of 10-homolupinanoyl-2-R-phenothiazines

Pursuing our researches on quinolizidinyl derivatives of phenothiazine and on the ground of antidepressive, diuretic, antianginal and antiarrhythmic activities of several 10-(3-dialkylamino) propionylphenothiazines (as chloracizine, moricizine, etc.), six 10-homolupinanoyl-2-R-phenothiazines were prepared and subjected to a broad pharmacological screening with in vivo and in vitro assays. Most of these compounds exerted strong antiarrhythmic activity (compounds 1, 3 and 5 were comparable or superior to lidocaine and quinidine in three tests), calcium antagonism on guinea pig ileum and left atria, antagonism to smooth muscle contractile responses induced by several agents and inhibition of rabbit platelet aggregation induced by PAF and ADP. A few other activities were characteristic of single compounds, as antagonism to central and peripheral effects of oxotremorine 1, moderate antihypertensive activity 5, local anesthetic activity and antagonism to substance P 2, antiinflammatory activity with low or absent gastric irritation 2, 3, powerful saluretic action 6, inhibition of arachidonate induced platelet aggregation 1 and antagonism to PAF induced mortality 1, 4. The last activity is very unusual and deserves further investigation. The capacity of compound 1 to displace specific ligands from several receptors was also investigated. Significant binding for M1 (IC50 = 0.03 microM), M3 (IC50 = 10 microM), sigma receptors and Na+ channels (IC50 = 1 microM) were evidentiated.

Anti-allergy actions of alkylphenyl alpha-D-mannopyranosides

The inhibitory effects of alkylphenyl alpha-D-mannopyranosides on histamine release from rat peritoneal mast cells induced by an antigen-antibody reaction were examined. Among the compounds tested, 2,4,6-trimethylphenyl alpha-D-mannopyranoside exhibited the strongest inhibitory effect. Furthermore, the 2,4,6-trimethylphenyl alpha-D-mannopyranoside suppressed the Schultz-Dale reaction and 48 h homologous passive cutaneous anaphylaxis (PCA), suggesting that this compound may be a useful lead compound in the development of novel anti-allergy drugs.

The inhibitory effect of magnolol on cutaneous permeability in mice is probably mediated by a nonselective vascular hyporeactivity to mediators

In the present study, we demonstrated the inhibitory effect of magnolol on the plasma leakage in passive cutaneous anaphylactic (PCA) reaction, neurogenic inflammation, dorsal skin and ear edema in mice. Hind-paw skin plasma extravasation caused by antidromic stimulation of the saphenous nerve was reduced in mice pretreated with magnolol, diphenydramine or methysergide, but not with indomethacin. Ear edema formation in the PCA reaction was reduced by magnolol in dose-dependent manner. In addition, histamine-, serotonin-, compound 48/80-, bradykinin- and substance P-induced ear edema in mice was also suppressed by magnolol. A dose- and time-dependency of the inhibitory effect of magnolol was demonstrated in histamine- and compound 48/80-induced dorsal skin edema. The maximal inhibitory effect produced by a single dose of magnolol (10 mg/kg) persisted for 1 h, and significant suppression lasted for at least 3 h. In compound 48/80-pretreated mice, the histamine content of the ear was greatly reduced. Bradykinin- and substance P-induced ear edema in compound 48/80-pretreated mice was less severe than that seen in normal mice, but was still significantly reduced by magnolol pretreatment. Moreover, the inhibitory effect of magnolol was more marked than that of diphenhydramine combined with methysergide. These results suggest that the inhibitory effect of magnolol on local edema formation probably occurs through a nonselective inhibition on vascular tissue to prevent the permeability change caused by various mediators.

Effects of MKS-492 on antigen-induced bronchoconstriction and allergic reaction in guinea pigs and rats

Effects of R[+]-8-([1-[3,4-dimethoxyphenyl]-2-hydroxyethyl]amino) -3,7-dihydro-7-[2-methoxyethyl]-1,3-dimethyl-1H-purine-2,6-dione (MKS-492), a reported type III isozyme inhibitor of cyclic nucleotide phosphodiesterase, on antigen- or platelet activating factor (PAF)-induced bronchoconstriction and allergic reactions in guinea pigs and rats were investigated. 1) MKS-492 inhibited antigen-induced bronchoconstriction in guinea pigs. Aminophylline also inhibited the reaction. 2) MKS-492 inhibited PAF-induced bronchoconstriction and inhibited the increase in airway responsiveness to histamine in guinea pigs, although aminophylline failed to affect these reactions. 3) MKS-492 relaxed guinea pig tracheal muscle in vitro more potently than aminophylline. 4) MKS-492 inhibited leukotriene B4 (LTB4)-induced airway eosinophilia in guinea pigs. 5) MKS-492 inhibited passive cutaneous anaphylaxis and mediator-induced skin reactions in rats more potently than aminophylline. Both drugs inhibited antigen- and phospholipase A2-induced histamine release from guinea pig lung tissue. 6) MKS-492 inhibited PAF-induced O2- generation from guinea pig alveolar macrophages. These results indicate that MKS-492 is a more potent inhibitor of allergic bronchoconstriction and PAF- or LTB4-induced inflammatory reactions in guinea pigs and the allergic cutaneous reactions in rats when compared to aminophylline.

Preparation of substituted N-phenyl-4-aryl-2-pyrimidinamines as mediator release inhibitors

The role of immunologically released mediators, such as histamine, leukotrienes, and platelet-activating factor, is well-established for asthma and other allergic disorders. Developing therapeutic agents which would block mediator release from mast cells and other relevant cell types would provide a rational approach to asthma therapy. Using human basophil as a screen, a series of 4-aryl-2-(phenylamino)pyrimidines was found which inhibited mediator release. These compounds were prepared by condensing acetyl heterocycles with dimethylformamide dimethyl acetal to form enaminones which are cyclized with aryl guanidines to give pyrimidines. After examining a large number of analogs, N-[3-(1H-imidazol-1-yl)phenyl]-4-(2-pyridinyl)-2- pyrimidinamine (1-27) was chosen for toxicological evaluation.

E-type prostaglandins enhance local oedema formation and neutrophil accumulation but suppress eosinophil accumulation in guinea-pig skin

1. Prostaglandins possess both pro- and anti-inflammatory actions depending on their route of administration and the experimental model used. In this study, we have investigated the effect of locally injected prostaglandins on oedema formation, neutrophil accumulation and eosinophil accumulation in inflammatory responses in guinea-pig skin. 2. Prostaglandin E1 (PGE1) significantly enhanced local oedema formation induced by zymosan-activated plasma (ZAP), bradykinin and in a passive cutaneous anaphylactic (PCA) reaction. The accumulation of ZAP-induced 111In-labelled neutrophils was also significantly enhanced by PGE1. In addition, the prostacyclin analogue, iloprost, enhanced ZAP-induced responses. 3. In contrast PGE1 decreased the accumulation of 111In-labelled eosinophils in skin sites. This was demonstrated on eosinophil accumulation and local oedema formation induced by PAF, compound 48/80 and in the PCA reaction. PGE2 also suppressed eosinophil accumulation while iloprost had no detectable effect. 4. Isoprenaline inhibited eosinophil accumulation in a dose-dependent manner with no effect on local oedema formation, except in the case of responses to ZAP where suppression was observed. 5. The vasodilator neuropeptide, calcitonin gene-related peptide (CGRP), enhanced local oedema formation but had no detectable effect on eosinophil accumulation. 6. In conclusion, the magnitude of a given response to an inflammatory mediator in vivo depends on the net effect of stimulation of several cell types e.g. arteriolar smooth muscle cells, microvascular endothelial cells, mast cells and accumulating leukocytes. In this study, we have demonstrated that different components of the inflammatory response in guinea-pig skin can be differentially modulated by E-type prostaglandins and isoprenaline, suggesting that cyclic AMP has an important regulatory role.

Strain differences in change in airway responsiveness after repeated antigenic challenge in three strains of rats

1. The strain differences in 2,4-dinitrophenylated-Ascaris antigen-induced airway hyperresponsiveness (AHR) were investigated in three strains of rats: Brown-Norway (BN), Long-Evans Cinnamon (LEC) and Wistar. 2. Fourty-eight hour-passive cutaneous anaphylaxis titers after repeated challenge were highest in BN and lowest in LEC. 3. Twenty-four hours after the last challenge, a marked AHR and significant increase in wet/dry weight ratio of the main bronchus were observed only in Wistar. 4. Only the isolated bronchus of the challenged Wistar among the strains showed hyperresponsiveness to acetylcholine. 5. Wistar may be the best strain for antigen-induced AHR.

Effects of quinotolast, a new orally active antiallergic drug, on experimental allergic models

The effects of a new antiallergic drug, quinotolast [sodium 5-(4-oxo-1-phenoxy-4H-quinolizine-3-carboxamido)tetrazolate monohydrate], were studied and compared with those of tranilast, amlexanox, pemirolast, repirinast and disodium cromoglycate (DSCG) in experimental allergic models. Quinotolast potently inhibited such type I allergic reactions as passive cutaneous anaphylaxis (PCA) and anaphylactic bronchoconstriction in rats by both intravenous and oral dosing. All of these effects were stronger than those of the reference drugs tested. Quinotolast inhibited histamine release from rat peritoneal cells, but it had no antagonistic effect on histamine-, serotonin-, platelet activating factor- or bradykinin-induced cutaneous reactions in rats. Moreover, it was clearly demonstrated that quinotolast and DSCG had a cross tachyphylaxis to inhibit PCA in rats, suggesting that these drugs, at least in part, share the same mechanism of action. Furthermore, quinotolast potently inhibited PCA in guinea pigs in which DSCG and other reference drugs showed poor inhibitory activity. Quinotolast also showed stronger inhibitory effects on histamine and peptide leukotrienes release from guinea pig lung fragments or mouse cultured mast cells than the other drugs tested. Thus, the effect of quinotolast on type I allergic reaction would seem to be based on an inhibition of mediator release from inflammatory cells including mast cells. The results suggest that quinotolast will be beneficial in the treatment of type I allergy-related diseases.

[Synthesis of 4-methyl-6-phenyl-thieno(2,3-d)pyrimidines with a formamidino- or oxalamidocarbonic acid residue with antianaphylactic activity]

3-Amino-4-methyl-6-phenyl-thieno[2,3-d]pyrimidine-2-carbonic acid alkylesters 1a, b were hydrolyzed to the potassium salt of the carbonic acid 2. Cyclization of 2 with acetanhydride yielded the tricyclic 1,3-oxazinone derivative 4. This compound reacted with pyrrolidine by different conditions of reaction to give the bisamide 7, the acetamidino carbonic acid 5 and their decarboxylated product 6. Compound 1a yielded with Vilsmeier reagents the formamidino compound 3. 3-Amino-thieno[2,3-d]pyrimidin-2-carbonitrile gave under different conditions of reaction with oxalic acid diethylester or with oxalic acid ethylester chloride the tetracyclic 4-methoxy-9-methyl-7-phenyl-thieno[2,3-d:4,5-d']dipyrimidine-2-car bonic acid methylester 10 or the N-(2-cyano-4-methyl-6-phenyl-thieno[2,3-d]pyrimid-3-yl)oxalamid ic ethylester 12. These compounds were hydrolyzed to give the carbonic acids 11 and 13. Some of the synthesized substances showed an antianaphylactic activity.

Hylan gel biomaterial: dermal and immunologic compatibility

Hylan, a hyaluronan derivative, was chemically cross-linked with divinyl sulfone to produce a water-insoluble gel. This gel was fragmented into a gel slurry and evaluated for particle size, biocompatibility, and residence times in selected tissues. Hylan gels used in this study are made up of pseudoplastic, deformable gel particles with greater elasticity (at all frequencies) and greater viscosity (shear rates, 0.01 sec-1) than the water soluble hylan polymer. Hylan gel was injected intradermally and subdermally in mice and was found to produce a minimal reaction at 24 h; thereafter (up to 7 weeks) there was no significant tissue reaction. Intradermal injection of [3H]-hylan gel in guinea pigs revealed a minimal tissue reaction after 1 week, and measurement of radioactivity in the tissue at 1, 2, and 4 weeks revealed only a slight decrease in the total amount of injected radioactivity. The immunogenic activity of hylan gel was evaluated in rabbits; unmodified hylan gel, degraded hylan gel, and hylan gel ovalbumin conjugate were used to immunize rabbits. No antibody production to any hylan gel sample was detected, although control rabbits immunized with ovalbumin developed titers > 400 of antiovalbumin antibodies by day 21, as measured by the passive cutaneous anaphylaxis assay (PCA). Last, serum from owl monkeys (Aotus trivirgatus) in which hylan gel had been placed intravitreally for up to 3 years contained no detectable anti-hylan gel antibodies (PCA assay). Skin tests on these monkeys were also negative.

[Synthesis of 11-aryl-7,8,9,10-tetrahydro-1,2,3-triazino-(4',5':4,5)-thienol- -(2,3-b)-quinolines with antianaphylactic action]

Title compounds of structure B with an oxo function in position 4 of the triazine ring were synthesized by reaction of the aminocarboxamides A with sodium nitrite in acetic acid. Aminocarbonitriles of structure H yielded with sodium nitrite in acetic acid and hydrochloric acid the 4-chloro derivatives I. These compounds gave with N-nucleophiles, methoxide or thiourea the substances J. Tetracyclic compounds with a hydroxyethyl or a piperidinoethyl residue in position 3 in the triazine ring (E, G) were also prepared. Some of the investigated compounds showed an antianaphylactic activity.

[Synthesis of new pyrido-(3',2':4,5)-thieno-(3,2-d)-1,2,3-triazine derivatives as antianaphylactics]

Some new pyrido[3',2':4,5]thieno[3,2-d]1,2,3-triazine-4(3H)-ones (C) were synthesized from 2-thioxo-1,2-dihydro-3-carbonitriles (A) via the 3-amino-thieno[2,3-b]pyridine-2-carboxamides (B). Substances of structure A were converted to 3-amino-thieno[2,3-b]pyridine-2-carbonitriles (G) which yielded the desired 4-amino substituted compounds I via the tricyclic 4-chloro-pyrido[3',2':4:5]thieno[3,2-d]1,2,3-triazines (H) by the reaction with N-nucleophiles. Some of the investigated compounds showed a respectable antianaphylactic activity.

[Synthesis of thieno(2,3-b)pyridines with oxalamidic acid or an oxalamidic alkylester residues and of 4-alkoxy-pyrido(3',2':4,5)thieno(3,2-d)pyridine-2-carboxylic acid derivates]

N-(2-Alkoxycarbonyl-thieno[2,3-b]pyrid-3-yl)oxalamide acid alkylester B were synthesized by the reaction of 3-amino-2-carboxylic esters A with oxalic acid diethylester in presence of sodium alkoxides. The 3-amino-2-cyano-thieno[2,3-b]pyridines C yielded under the same conditions via the N-(2-cyano-thieno[2,3-b]pyrid-3-yl)oxalamidic acid alkylesters D/1-D/4 the 4-alkoxy-pyrido[3',2':4,5]thieno[3,2-d]pyrimidine-2-carboxylic acid alkylesters E/1-E/8. The compounds D/1, D/2 and E/1-E/5 were hydrolyzed to give the corresponding carboxylic acids. The 3-amino-furo[2,3-b]pyridine-2-carboxylic acid ethylester H reacted with oxalic ethylester chloride to give the oxalamide ethylester I. The synthesized substances showed an antinaphylactic activity.

Piperidineacrylate derivatives as potential antiallergy agents

A new series of piperidineacrylate derivatives was prepared and evaluated for antiallergic activity. Most of the compounds showed potent activities in the rat passive cutaneous anaphylaxis (PCA) assay. In particular, ethyl 1-[2-bis(4-fluorophenyl)methoxyethyl]-4-piperidineacrylate (1a) was more potent than oxatomide and terfenadine in this assay, and was selected for further study. Some pharmacological properties of 1a are presented.

Effects of DS-4574, a new orally active antiallergic agent, in experimental allergic and inflammatory models

The anti-allergic and anti-inflammatory activities of DS-4574, which possesses leukotriene antagonism and inhibits the release of immunologically stimulated mediators such as histamine and leukotrienes, were evaluated in several animal models. DS-4574 had dose-dependent inhibitory effects on IgE-mediated passive cutaneous anaphylaxis and the passive Arthus reaction in rats and the phase I response of Forssman antibody-induced bronchoconstriction. In contrast, this compound had no effect on the phase II response of Forssman antibody-induced bronchoconstriction in guinea pigs, the reverse cutaneous anaphylaxis in rats, complement-dependent hemolysis of sheep erythrocytes and the delayed-type hypersensitivity induced by methylated bovine serum albumin in mice. The results obtained in a double sensitization with two IgE antibodies suggested that DS-4574, as well as disodium cromoglycate, did not impair antigen-antibody combination but prevents the release of chemical mediators such as histamine. DS-4574 also had a weak inhibitory activity on carrageenin paw edema in rats, arachidonic acid ear edema in mice and adjuvant arthritis in rats. In addition, this compound inhibited increased vascular permeability in rat skin induced by leukotriene D4 and platelet activating factor-induced pleurisy in rats in a dose-dependent manner. These results indicate that DS-4574 inhibited type III allergic reactions and some inflammatory reactions. Therefore, DS-4574 could be useful in the treatment of allergic diseases such as asthma.

[Synthesis of furo(2,3-b)pyridine amidines with antianaphylactic activity]

The synthesis of furo[2,3-b]pyridine formamidines (D/1-D/11, F) was realized by the reaction of the 3-amino-furo[2,3-b]pyridines C/1-C/11 and E, substituted in position 2 with a carbonyl moiety with dimethylformamide/phosphoroxide chloride or with N-formyl-piperidine or N-formyl-morpholine and phosphoroxide chloride. The acetamidines H were yielded from 4-oxo-4H-3-methyl-pyrido[3',2':4,5]furo[3,2-d]1,3-oxazines with aminoethanol. The 4-oxo-4H-3-amino-3,4-dihydro-pyrido[3',2':4,5]furo[3,2-d]pyrimidines K and M reacted with dimethylformamide/phosphoroxide chloride to give the tricyclic formamidines L and K. The described amidines showed antianaphylactic activity.

[The search for new antiallergy compounds among a number of coumarin derivatives and the study of their mechanisms of action]

The antiallergic effects of new novel synthetic coumarine-3-carboxylic acid derivatives were studied in a rat model of passive cutaneous anaphylaxis. The most potent agent was found and tested for mechanisms of its specific pharmacological action. Its capacity of suppressing immediate hypersensitivity in various animal species was demonstrated to be due to its concomitant action on the pathochemical and pathophysiological stages of the allergic process.

Immediate inhibitory effect of methylprednisolone suleptanate (U-67590A) on antigen-induced cutaneous and airway anaphylactic responses in guinea-pigs

1. Inhibitory effects of water-soluble glucocorticoids administered intravenously were examined on skin and airway reactions caused by antigen challenge or chemical mediators in guinea-pigs. 2. Methylprednisolone suleptanate (U-67590A) which is an analogue of methylprednisolone, produced immediate inhibition of 3-h and 7-day homologous passive cutaneous anaphylaxis (PCA) reactions, but not of histamine- or bradykinin-induced cutaneous vascular permeability, when administered 10 min before antigen challenge. In contrast, methylprednisolone succinate (MP) or dexamethasone (DXM) administered 10 min before antigen challenge failed to show an immediate inhibitory effect on the PCA or mediator-induced reactions. When administered 1 to 5 h before antigen challenge, all the steroids used in this study reduced both PCA and mediator-induced reactions. 3. Pretreatment with cycloheximide almost completely abolished the late inhibition of 3-h PCA and histamine reactions produced by U-67590A or MP, but it did not affect the immediate inhibition of 3-h PCA produced by U-67590A. 4. U-67590A also demonstrated immediate inhibitory effects on antigen-induced bronchoconstriction in guinea-pigs actively sensitized with ovalbumin even when administered 10 min before antigen challenge, whereas MP and DXM failed to show the immediate inhibitory effect. When administered 3 h before antigen challenge, all the steroids used in this study reduced the response to antigen. 5. The late inhibitory effect of U-67590A administered 3 h before antigen challenge was almost completely abolished by treatment with cycloheximide or 17 alpha-methyltestosterone, whereas the immediate inhibition produced by U-67590A administered 10 min before challenge was not affected by this treatment. 6. U-67590A administered 10 min or 3 h before challenge did not affect the bronchoconstriction induced by histamine or leukotriene D4.7. Release of histamine from lung fragments of sensitized guinea-pigs in vitro was inhibited by U-67590A.8. The present experiments indicate that U-67590A demonstrated dual, immediate and late, inhibitory effects. The former are independent of protein synthesis and may be associated with non-genomic direct action on the mediator-releasing process without affecting mediator-induced reactions. The latter share common inhibitory actions with other glucocorticoids which are dependent on protein synthesis through gene expression.

[Synthesis of N-(2-carboxy-thieno(2,3-b)pyridin-3-yl)-formamidines corresponding alkyl esters with antianaphylactic activity]

A lot of N-(2-carboxy-thieno[2,3-b]pyridin-3-yl)formamidines especially in form of their amine salts--were synthesized by reaction of 3-amino-thieno[2,3-b]pyridine-2-carboxylic acids with dimethylformamide/phosphoroxide chloride or by reaction of 4-oxo-4H-pyrido[3',2':4,5]thieno[3,2-d]1,3- oxazines with amines. Carboxylic acid alkylesters of this structure were yielded from 3-amino-thieno[2,3-b]pyridine-2-carbonic acid alkylesters by reaction with dimethylformamide/phosphoroxide chloride or with N-formyl-piperidine or N-formyl-morpholine and phosphoroxide chloride. The compounds showed antianaphylactic activity.