Expression of CysLT2 receptors in asthma lung, and their possible role in bronchoconstriction.

Background: The expression and functional role of CysLT2 receptors in asthma have not been clarified. In this study, we evaluated CysLT2 receptors expression, and effects of CysLT2-and CysLT1/2-receptor antagonists on antigen-induced bronchoconstriction using isolated lung tissues from both asthma and non-asthma subjects.

Methods: CysLT1 and CysLT2 receptors expression in asthma and non-asthma lung tissue preparations was examined in immunohistochemistry experiments, and their functional roles in antigen-induced bronchoconstriction were assessed using ONO-6950, a dual CysLT1/2-receptor antagonist, montelukast, a CysLT1 receptor antagonist, and BayCysLT2RA, a CysLT2 receptor-specific antagonist.

Dietary deficiencies of unsaturated fatty acids and starch cause atopic dermatitis-like pruritus in hairless mice.

Hairless mice fed with a special diet (named HR-AD) show atopic dermatitis (AD)-like pruritic skin inflammation that is almost completely resolved with the supplementation of an unsaturated fatty acid (UFA), the linoleic acid (LA). This suggests that the dietary deficiency of LA is the key cause of this dermatitis. However, because there is no appropriate control diet for HR-AD, the involvement of other dietary ingredients cannot be ruled out.

Deficiency of n-6 polyunsaturated fatty acids is mainly responsible for atopic dermatitis-like pruritic skin inflammation in special diet-fed hairless mice.

Hairless mice fed a special diet, HR-AD, develop atopic dermatitis (AD)-like skin inflammation with skin barrier defects and itch-related scratching; however, the ingredient(s) causing the dermatitis remains unclear. In this study, we examined whether deficiency of certain polyunsaturated fatty acids (PUFAs) is involved in HR-AD-induced AD. High-purity PUFAs were given to HR-AD-fed mice by dietary supplementation or gavage.

Inhibitory effect of chitosan-containing lotion on scratching response of hairless mice with atopic dermatitis-like dry skin.

In this study, using a special diet-induced mouse model of atopic dermatitis, we tested the effect of chitosan-containing lotion (CL) on itch-related scratching associated with barrier-disrupted dry skin. HR-1 hairless mice fed a special diet exhibited apparent dry skin symptoms characterized by decreased skin hydration and increased transepidermal water loss. In the special diet-fed mice, scratching behavior was markedly enhanced for 60 min after oral administration of ethanol.

Effect of Ganoderma lucidum on pollen-induced biphasic nasal blockage in a guinea pig model of allergic rhinitis.

Ganoderma lucidum (GL), an oriental medical mushroom, has been used in Asia for the prevention and treatment of a variety of diseases. However, the effect of GL on allergic rhinitis has not been well defined. The current study describes the inhibitory effect of GL on the biphasic nasal blockage and nasal hyperresponsiveness induced by repeated antigen challenge in a guinea pig model of allergic rhinitis.

Inhibition of hematopoietic prostaglandin D synthase improves allergic nasal blockage in guinea pigs.

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.

Pulmonary emphysema induced by cigarette smoke solution and lipopolysaccharide in guinea pigs.

Exposure of animals to cigarette smoke for longer than 3 months leads to the development of chronic obstructive pulmonary disease (COPD) showing pulmonary emphysema. We attempted to create a COPD model with emphysema that could be established in a shorter period of time. Guinea pigs were intratracheally treated once a day on days 0-3, 5-8, 10-13 and 15-18 with a cigarette smoke solution (CSS), which was prepared by bubbling a stream of smoke into saline.

Ethanol aggravates itch-related scratching in hairless mice developing atopic dermatitis.

In patients with atopic dermatitis, alcoholic beverages can sometimes trigger or enhance itching. We have previously reported that HR-1 hairless mice fed a commercial special diet, HR-AD, but not a normal diet, develop atopic dermatitis-like skin inflammation with prolonged spontaneous scratching, and that skin barrier dysfunction is involved in the basal scratching. In the present study, the effects of ethanol on itch-related scratching were examined in this mouse model.

Absence of nasal blockage in a Japanese cedar pollen-induced allergic rhinitis model mouse.

Background: Japanese cedar pollen-induced allergic rhinitis in a guinea pig model clearly induced not only sneezing but also biphasic nasal blockage. To date, there have only been a few reports on models of murine allergic rhinitis which clearly show nasal blockage. Therefore, in order to try and develop such a model, we administered multiple dosages of intranasal pollen or purified antigen protein Cry j 1.

Effect of TA-270, a novel quinolinone derivative, on antigen-induced nasal blockage in a guinea pig model of allergic rhinitis.

TA-270 (4-hydroxy-1-methyl-3-octyloxy-7-sinapinoylamino-2(1H)-quinolinone) is a novel quinolinone derivative that has been demonstrated to possess an anti-oxidative activity against peroxynitrite, a potent oxidant, that is generated by the reaction of nitric oxide with superoxide anions. The current study describes the inhibitory effect of TA-270 on the biphasic nasal blockage induced by repeated antigen challenge in an allergic rhinitis guinea pig model. In the present in vitro study, TA-270 potently inhibited the oxidative reaction induced by peroxynitrite (IC(50)=79 nM).

Effect of local nasal immunotherapy on nasal blockage in pollen-induced allergic rhinitis of Guinea pigs.

Background: As a non-injection route for immunotherapy, local nasal immunotherapy has been examined in allergic rhinitis patients. However, it is unclear how the immunotherapy affects sneezing, biphasic nasal blockage and nasal hyperresponsiveness. Thus, we evaluated the therapeutic effects of nasal immunotherapy on the symptoms of guinea pig allergic rhinitis.

Effects of multiple dexamethasone treatments on aggravation of allergic conjunctivitis associated with mast cell hyperplasia.

In a Japanese cedar pollen-induced allergic conjunctivitis model in guinea pigs, symptoms were aggravated by repeated pollen challenges. In addition, the number of mast cells in the conjunctiva was increased by multiple challenges. The amount of a mast cell mediator, histamine in ophthalmic lavage fluid was also increased by multiple challenges.

Involvement of peroxynitrite in pollen-induced nasal blockage in guinea pigs.

Nitric oxide (NO) has been implicated in early and late phase nasal blockage in a Japanese cedar pollen-induced experimental allergic rhinitis guinea pig model. In this study, we investigated the role of peroxynitrite, which is formed by a rapid reaction of NO with superoxide anion, in the antigen-induced biphasic nasal blockage. Sensitized guinea pigs were repeatedly challenged by pollen inhalation once every week.

Polycyclic aromatic hydrocarbons aggravate antigen-induced nasal blockage in experimental allergic rhinitis.

It has been hypothesized that air pollution has played a role in the increase in allergy prevalence. However, it remains unclear what exact roles are played by polycyclic aromatic hydrocarbons (PAHs), which are encountered in the environment in the form of air pollution, in allergic rhinitis. Thus, we examined whether benzo(a)pyrene (BaP) and 1-nitropyrene (1-NP), representative PAHs, aggravate allergic rhinitis symptoms, using a guinea-pig model.

Nasal blockage induced by oral administration of non-steroidal anti-inflammatory drugs in a guinea-pig model of allergic rhinitis.

To elucidate the mechanisms underlying nasal symptoms in patients with aspirin hypersensitivity, we evaluated the effects of orally administered non-steroidal anti-inflammatory drugs (NSAIDs) on the nasal patency of guinea pigs with cedar pollen-induced chronic allergic rhinitis. Indomethacin (10 mg/kg) administered 1 h before a pollen challenge amplified the antigen-induced nasal blockage. More interestingly, even in the absence of the pollen challenge, indomethacin induced nasal blockage at 30 min at 4 h after administration.

Involvement of galectin-9 in guinea pig allergic airway inflammation.

Background: There is little information about the involvement of galectin-9 (Gal-9) in allergic inflammation. Thus, we investigated the role of Gal-9 in asthma model guinea pigs.

Methods: Airway resistance (R(aw)) was measured using a double-flow plethysmograph system.

Development of numerous nerve fibers in the epidermis of hairless mice with atopic dermatitis-like pruritic skin inflammation.

Itching is the most important symptom in atopic dermatitis because the persistent scratching in response to itching aggravates the disease. However, the etiologic mechanisms of itching in atopic dermatitis remain uncertain. HR-1 hairless mice fed a special diet, HR-AD, develop atopic dermatitis-like symptoms with prolonged scratching episodes.

Different mechanisms between thromboxane A2- and leukotriene D4-induced nasal blockage in guinea pigs.

Although thromboxane (TX)A2 is involved in allergic rhinitis, the mechanisms inducing nasal blockage have not been elucidated. We evaluated the roles of nasal mucosal vascular changes following intranasal instillation of the TXA2 analog U-46619 or leukotriene (LT)D4 to induce nasal blockage in a guinea pig model of allergic rhinitis. Both U-46619- and LTD4-induced nasal blockages in sensitized animals were swiftly and completely suppressed by a vasoconstrictor, naphazoline.

Detection of new antigenic proteins in Japanese cedar pollen.

In Japan, an increasing number of people suffer from pollenosis, a typical atopic disease. Japanese cedar (Cryptomeria japonica) pollen is the most common allergen that causes pollenosis. Although Cry j 1 and Cry j 2 are the common allergenic proteins contained in the pollen, there is a small population of patients who exhibit positive skin reactions to the pollen extract but are negative for both Cry j 1 and Cry j 2.

Involvement of skin barrier dysfunction in itch-related scratching in special diet-fed hairless mice.

HR-1 hairless mice fed with a special diet develop atopic-like dry skin, characterized by increased transepidermal water loss, and prolonged bouts of spontaneous scratching. In this study, the role of the skin barrier dysfunction in the prolongation of scratching was evaluated. Although the prolonged scratching was dose-dependently inhibited by opioid receptor antagonist naloxone, neither H(1) receptor antagonist, mepyramine, nor 5-HT(1/2) receptor antagonist, methysergide, affected it.

Induction of a late asthmatic response associated with airway inflammation in mice.

To investigate mechanisms underlying the late asthmatic response, we developed a murine model using repetitive intratracheal antigen challenge. BALB/c mice sensitized by i.p.

Effect of oral immunotherapy on nasal blockage in experimental allergic rhinitis.

We previously reported that when Japanese cedar pollen was prophylactically p.o. administered before a sensitization stage in a guinea-pig model of allergic rhinitis, pollen-induced nasal blockage was suppressed.