prostaglandin-d2 and Nasal-Obstruction

Topics: Histamine; Humans; Kinins; Leukotrienes; Nasal Obstruction; Platelet Activating Factor; Prostaglandin D2; Rhinitis, Allergic, Perennial; Rhinitis, Allergic, Seasonal; Substance P

Nasal congestion in allergic rhinitis results from tissue edema and vasodilatation in the nasal mucosa. Of the mediators released by mast cells in response to allergens, prostaglandin (PG) D(2) is regarded as the most potent inducer of nasal congestion. Intranasal administration of PGD(2) reproduces the nasal blockade experienced by patients with seasonal allergic rhinitis (SAR) via its action on the PGD(2) (DP) receptor to induce nasal vasodilatation. Intranasal challenge with PGD(2) can be a useful tool for evaluating DP-receptor antagonists.. The main purpose of this study was to examine the ability of MK-0524, a DP receptor antagonist in development for the treatment of SAR, to block PGD(2) induced nasal congestion in healthy volunteers.. To this end, a double-blind, placebo-controlled, randomized, 3-period study was performed in 15 healthy subjects. During each period, subjects received MK-0524 25 mg, MK-0524 100 mg or placebo qd for 3 days. Twenty-four hours following the last dose, nasal provocations with PGD(2) were performed to determine the PD(75), which is the intranasal dose of PGD(2) that provokes a 75% increase in baseline total nasal airway resistance as performed by active anterior rhinomanometry.. Following treatment with MK-0524, the PD(75) (mean+/-SD) was significantly shifted from 15.8 +/- 18.3 mug/nostril during the placebo period to more than 512 mug/nostril both following the 25- and 100-mg (maximum challenge dose tested) dose regimen.. Whether this >45 fold increase in PD(75) will induce a clinically meaningful effect of MK-0524 will require clinical study in participants with SAR.

Topics: Administration, Oral; Adult; Cross-Over Studies; Dose-Response Relationship, Drug; Double-Blind Method; Female; Humans; Indoles; Male; Nasal Obstruction; Prostaglandin D2; Receptors, Immunologic; Receptors, Prostaglandin; Rhinitis, Allergic, Seasonal; Rhinomanometry

The clinical importance of leukotrienes in human allergy has not been defined, in part because there have been no selective 5-lipoxygenase inhibitors that have been effective and safe for use in humans. To address the hypothesis that stimulated leukotriene synthesis causes symptoms of immediate-hypersensitivity reactions in vivo, I investigated the effects of a new 5-lipoxygenase inhibitor, A-64077, on provoked allergic nasal symptoms and mediator release in a double-blind, randomized, placebo-controlled study. Eight subjects with allergic rhinitis underwent nasal challenge on two occasions after an oral dose of 800 mg of A-64077 or an identical-appearing placebo.. Allergen-induced nasal congestion was significantly attenuated (P less than 0.02) by A-64077; peak levels of leukotriene B4 (median, 684 pg per milliliter) and 5-hydroxyeicosatetraenoic acid (median, 704 pg per milliliter) in nasal-rinse fluids were markedly reduced (to 67 and 185 pg per milliliter, respectively; P less than 0.01), whereas levels of prostaglandin D2 were not. Histamine release and sneezing were not reduced significantly by A-64077, but there was a significant correlation (P less than 0.01) between the changes in these variables within subjects. The mean (+/- SEM) stimulated synthesis of leukotriene B4 in whole blood ex vivo was markedly reduced by A-64077 (from 153 +/- 19 to 20 +/- 9 ng per milliliter, P less than 0.01), and the specificity of A-64077 for 5-lipoxygenase inhibition was verified by its lack of effect on the synthesis of serum thromboxane B2 or 12-hydroxyeicosatetraenoic acid.. These results provide direct evidence of an important role for the 5-lipoxygenase products of arachidonic acid in allergic rhinitis and support the notion that further experiments in this area may lead to new therapeutic approaches to allergic disorders.

Topics: Double-Blind Method; Female; Histamine Release; Humans; Hydroxyeicosatetraenoic Acids; Hydroxyurea; Leukotriene B4; Leukotrienes; Lipoxygenase Inhibitors; Male; Nasal Obstruction; Nasal Provocation Tests; Prostaglandin D2; Rhinitis, Allergic, Perennial; Rhinitis, Allergic, Seasonal; Sneezing

Nasal obstruction is one of the most bothersome symptoms of allergic rhinitis (AR) affecting sleep-related quality of life in AR patients. Although several treatments were tested to control nasal obstruction, some patients with moderate to severe AR do not respond to current treatments, including the combined administration of different types of anti-allergic medicine. Thus, new options for AR treatment are needed. This study aimed to evaluate the effects of combined treatment with a novel inhibitor of hematopoietic prostaglandin D synthase (HPGDS), TAS-205, and different types of anti-allergic medicine on nasal obstruction in AR. Firstly, we demonstrated that TAS-205 selectively inhibited prostaglandin D

Topics: Acetates; Animals; Anti-Allergic Agents; Cell Line; Cyclopropanes; Disease Models, Animal; Drug Synergism; Drug Therapy, Combination; Enzyme Inhibitors; Guinea Pigs; Humans; Intramolecular Oxidoreductases; Lipocalins; Male; Morpholines; Nasal Mucosa; Nasal Obstruction; Ovalbumin; Piperidines; Prostaglandin D2; Pyrroles; Quality of Life; Quinolines; Rats; Rhinitis, Allergic; Sulfides; Terfenadine

Allergic rhinitis is the most common allergic disease, displaying the typical nasal symptom of congestion. Prostaglandin D(2) (PGD(2)), a chemical mediator released in large amounts by mast cells upon allergic stimulation in humans, is known to be involved in nasal congestion. However, the mechanism by which this congestion occurs remains unclear.. The effect of PGD(2) on the nasal airflow in guinea pigs was measured using a noninvasive approach that avoided any anesthetic effect. Isometric tension of isolated nasal mucosa and the nasal vascular corrosion resin cast technique were used to clarify the area of nasal mucosal vessels affected by PGD(2), and to examine the mechanism of PGD(2)-induced nasal congestion. Moreover, the involvement of second messengers in PGD(2)-induced mucosal relaxation was investigated.. PGD(2) induced an increase in intranasal pressure in a guinea pig model of rhinitis. Additionally, sinusoidal microvessel dilatation appeared around the septum using the vascular corrosion resin cast technique in the nasal mucosa. Moreover, relaxation of the nasal mucosa following stimulation of the prostanoid DP-1 receptor was associated with cAMP levels in the tissue.. PGD(2)-induced nasal congestion is caused by direct dilatation of the sinusoid vessels through the increase of cAMP levels in the nasal mucosa, demonstrating that the mechanism of PGD(2)-induced nasal congestion is different from other chemical mediators. Consequently, antagonists for the prostanoid DP-1 receptor would be an alternative approach for the relief of nasal congestion. Alternatively, the combined administration with antagonists for other mediators involved in nasal congestion may also be a valuable therapy for allergic rhinitis.

Topics: Animals; Cyclic AMP; Disease Models, Animal; Guinea Pigs; Male; Nasal Mucosa; Nasal Obstruction; Prostaglandin D2; Receptors, Prostaglandin; Rhinitis, Allergic, Perennial

Although it has been suggested that prostaglandin (PG) D(2) is involved in the pathogenesis of allergic rhinitis, whether the inhibition of hematopoietic PGD(2) synthase (H-PGDS) shows beneficial effects on allergic rhinitis has been unclear. We evaluated the effects of a selective H-PGDS inhibitor, TFC-007, on nasal symptoms on Japanese cedar pollen-induced allergic rhinitis of guinea pigs. Sensitized animals were challenged with the pollen once a week. TFC-007 (30mg/kg, p.o.) given once before a challenge almost completely suppressed PGD(2) production in the nasal tissue early and late after the challenge. Although pre-treatment did not affect the incidences of sneezing and early phase nasal blockage, late phase nasal blockage was partially but significantly attenuated; however, nasal eosinophilia was not suppressed. In contrast, when TFC-007 was given once 1.5h after the challenge, the late phase response was not affected. Collectively, PGD(2) produced by H-PGDS early after an antigen challenge can participate in the induction of late phase nasal blockage, although the mechanism may be independent of eosinophil infilatration. The strategy for H-PGDS inhibition may be beneficial for allergic rhinitis therapy.

Topics: Allergens; Animals; Cryptomeria; Enzyme Assays; Eosinophilia; Eosinophils; Guinea Pigs; Humans; Intramolecular Oxidoreductases; Lipocalins; Morpholines; Nasal Lavage Fluid; Nasal Obstruction; Pollen; Prostaglandin D2; Pyrimidines; Rhinitis, Allergic, Seasonal; Sneezing

We investigated the role of hematopoietic prostaglandin D synthase (H-PGDS) in biphasic nasal obstruction in allergic rhinitis using a new specific inhibitor, (N-methoxy-N-methyl)-4-(5-benzoylbenzimidazole-2-yl)-3,5-dimethylpyrrole-2-carboxamide hydrochloride (TAS-204). First, we developed a novel guinea pig model of allergic rhinitis. Guinea pigs sensitized to ovalbumin without adjuvant were challenged with intranasal exposure to ovalbumin once a week. After the 3rd antigen challenge, they exhibited biphasic nasal obstruction. Additionally, analysis of nasal lavage fluid revealed an increase in the level of prostaglandin D(2) in both early and late phases. Treatment with oral TAS-204 for 15 days during the period of antigen challenges suppressed increases in nasal airway resistance in both phases. It is noteworthy that the late phase nasal obstruction was almost completely abrogated by inhibiting H-PGDS alone. Eosinophil infiltration in nasal lavage fluid and nasal hyperresponsiveness to histamine was also reduced by TAS-204 administration. These findings suggest that H-PGDS plays a critical role in the development of allergic rhinitis, especially in the induction of late phase nasal obstruction.

Topics: Animals; Benzimidazoles; Dinoprostone; Disease Models, Animal; Eosinophils; Guinea Pigs; Histamine; Humans; Intramolecular Oxidoreductases; Leukotrienes; Lipocalins; Male; Nasal Lavage Fluid; Nasal Mucosa; Nasal Obstruction; Ovalbumin; Prostaglandin D2; Pyrroles; Rhinitis; Time Factors

We examined the role of prostanoid DP receptor in nasal blockage in an experimental allergic rhinitis model in guinea pigs. Local inhalation of prostaglandin D(2) (PGD(2)) to the nasal cavity resulted in an increase in intranasal pressure in guinea pigs actively sensitized by repeated antigen exposure but not in non-sensitized guinea pigs. Nasal hyperresponsiveness was observed when the guinea pigs were exposed to histamine and U-46619 (11alpha, 9alpha-epoxymethano-PGH(2); a thromboxane (TX) A(2) mimetic) after repeated antigen exposure. S-5751 ((Z)-7-[(1R,2R,3S,5S)-2-(5-hydroxybenzo[b]thiophen-3-ylcarbonylamino)-10-norpinan-3-yl]hept-5-enoic acid), a prostanoid DP receptor antagonist, inhibited not only PGD(2)-induced nasal blockage but also nasal hyperresponsiveness to histamine and U-46619 in sensitized guinea pigs. Combined exposure of the nasal cavity of guinea pigs to an aerosol of PGD(2) with histamine or U-46619 at sub-threshold concentrations synergistically caused a marked increase in intranasal pressure. These responses were significantly suppressed by S-5751. These results suggest that PGD(2) plays a critical role in the increase in intranasal pressure via prostanoid DP receptor, probably through synergistically enhancing the nasal response with other chemical mediators released from mast cells and other inflammatory cells activated by allergens.

Topics: 15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; Administration, Intranasal; Allergens; Animals; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Synergism; Guinea Pigs; Histamine; Male; Nasal Mucosa; Nasal Obstruction; Nose; Ovalbumin; Pressure; Prostaglandin D2; Receptors, Immunologic; Receptors, Prostaglandin; Rhinitis, Allergic, Perennial; Thiophenes; Time Factors

In perennial allergic rhinitis, patients are almost daily exposed to aeroallergens. This ongoing allergic reaction results in increased sensitivity to allergens and non-specific stimuli. It is generally known that inflammatory cells and mediators are involved in the pathogenesis of the allergic reaction.. To study the relationship between nasal hyperreactivity and nasal inflammation during natural allergen exposure.. In 48 patients with perennial allergic rhinitis and in 11 volunteers a nasal brush, a nasal lavage and a histamine challenge were performed. Nasal inflammation was estimated by the number of eosinophils, levels of albumin, tryptase, prostaglandin D2 (PGD2), eosinophil cationic protein (ECP) and leukotriene C4/D4/E4 (LTC4/D4/E4).. In contrast to PGD2 and tryptase, eosinophils (1.9 vs 0%, P = 0.0023), LTC4/ D4/E4 (17.51 vs 1.43 pg/mL, P < 0.0001) and albumin (8.61 vs 2.37 mg/mL, P = 0.0008) were significantly increased in rhinitis patients as compared with controls. Patients also showed increased responses to nasal histamine challenge assessed using a composite symptom score (21.5 vs 4 points, P < 0.0001). The nasal response to histamine was weakly correlated with the total number of eosinophils in the cytospin (correlation coefficient r = 0.38, P = 0.009).. Nasal hyperreactivity is correlated with the percentage of eosinophils in patients with perennial rhinitis. The patients' mediator profiles suggest that eosinophils are important in the ongoing allergic reaction and nasal hyperreactivity.

Topics: Adult; Blood Proteins; Chymases; Eosinophil Granule Proteins; Eosinophils; Female; Humans; Inflammation Mediators; Leukotrienes; Male; Nasal Obstruction; Nasal Provocation Tests; Prostaglandin D2; Rhinitis, Allergic, Perennial; Ribonucleases; Serine Endopeptidases; Tryptases

By using a microsuction technique, a quantitative determination of chemical mediators in nasal secretions was performed in 18 hay-fever patients and in a control group of 10 healthy volunteers. The authors then compared these quantitative data for mediators with objective nasal findings counting the number of sneezes, passive anterior rhinomanometry (PAR) and nasal inspiratory peak flow. A sampling protocol was designed with a follow-up of 3 days after nasal allergen challenge (NAC) in order to investigate both early and late allergic reactions. Median baseline concentrations of five major mediators were obtained: histamine, 19 ng/g; leukotriene C4 (LTC4), 5.7 ng/g. tryptase, 0; prostaglandin D2 (PGD2), 477 pg/g; eosinophil cationic protein (ECP), 105 ng/g. Significant increases in histamine (214 ng/g), LTC4 (20 ng/g) and tryptase (28 microU/g) were found, but a significant decrease occurred in ECP (47 ng/g) and PGD (226 pg/g) immediately after NAC in the patients studied. Most ECP concentrations (94%) increased slowly 1 h after NAC and reached a significantly higher level 24 h later. In evaluating nasal symptoms, sneezes were present in a high percentage of cases (76%) during the early phase but were uncommon during the late phase (29%). Total nasal obstruction occurred in 94% during the early phase. In contrast, unilateral nasal obstruction presented in 82% during the late phase, whereas total nasal obstruction was present only in 41%. The most common type of late phase nasal obstruction shown by PAR was alternating nasal obstruction.

Topics: Adolescent; Adult; Allergens; Blood Proteins; Case-Control Studies; Chymases; Eosinophil Granule Proteins; Female; Follow-Up Studies; Histamine; Humans; Inflammation Mediators; Inhalation; Leukotriene C4; Male; Middle Aged; Nasal Mucosa; Nasal Obstruction; Nasal Provocation Tests; Prostaglandin D2; Rhinitis, Allergic, Seasonal; Ribonucleases; Serine Endopeptidases; Sneezing; Tryptases