Recently, we showed that a methanol extract of Ganoderma lucidum inhibits scratching, an itch-related response, induced by intradermal injections of some pruritogens in mice. The present study investigated whether G. lucidum extract would inhibit allergic itch. In mice sensitized with an extract of salivary gland of mosquito (ESGM), an intradermal injection of ESGM elicited scratching, which wa...

We report the molecular cloning from foetal brain of the human potassium channel heag2. The cDNA encodes a protein of 988 amino acids, 73% identical to heag1. Heag2 is expressed in the brain, but is also found in a range of tissues including skeletal muscle. In oocytes, the channel is a non-inactivating outward rectifier, with dependence of activation rate on holding potential. Compared with he...

We investigated the effect of KW-4679 ((Z)-11-[(3-dimethylamino)propylidene]-6,11-dihydrodibenz[b, e]oxepin-2- acetic acid monohydrochloride), an orally active anti-allergic drug, on antigen-induced airway hyperresponsiveness using two different indicators, pulmonary resistance (RL) and dynamic lung compliance (Cdyn), in actively sensitized guinea pigs. Oral administration of KW-4679 (0.1 and 1...

There is a possibility that even a glass of grapefruit juice (GFJ) taken several hours before oral medication may enhance the bioavailability of many drugs, exaggerate the drug action, and increase the toxic effect by exaggerating the potency of the drug. This can be explained by inhibition of CYP3A4 in the small intestine by GFJ, thus suppressing drug metabolism. This interaction with GFJ is l...

Proteinase-activated receptor-2 (PAR2) participates in itch, but the role of the other subtypes of this receptor remain unknown. To investigate this issue, scratching, an itch-related behavior, was observed following intradermal injections of the activating peptides of PAR1-4 in mice. Activating peptides of PAR1, PAR2, and PAR4, but not PAR3, induced scratching. The antihistamine terfenadine su...

Fexofenadine hydrochloride (FFH), chemically known as (±)-4-[1-hydroxy-4-[4-(hydroxydiphenylmethyl)-1-piperidinyl]butyl]-a,a-dimethyl benzene aceticacid hydrochloride [1] is a active metabolite of terfenadine and is a second-generation histamine H1-receptor antagonist in piperidine-class drugs. These drugs are used in the treatment of seasonal allergic rhinitis, chronic idiopathic urticaria etc...

Astemizole and terfenadine, two potent non-sedative H1 antihistamines, had no effect on itch measured objectively as nocturnal scratching and subjectively on a 10 cm line. Trimeprazine, however, a more sedative but less potent H1 antihistamine, was antipruritic, as was nitrazepam, a sedative benzodiazepine. We concluded (a) that antipruritic drugs act centrally by a property related to sedation...

In the present study, we examined whether cholinergic agonists would elicit an itch-associated response in mice. When mice were given an intradermal injection of carbachol (1-10 nmol) or bethanechol (0.3-100 nmol) into the rostral back, they showed the dose-dependent increase of scratching. Nicotine (1-10 nmol) showed no effect. Pretreatment with naloxone, but not with terfenadine, significantl...