Brain histaminergic neurons play a prominent role in arousal and maintenance of wakefulness (W). H(3)-receptors control the activity of histaminergic neurons through presynaptic autoinhibition. The role of H(3)-receptor antagonists/inverse agonists (H(3)R-antagonists) in the potential therapy of vigilance deficiency and sleep-wake disorders were studied by assessing their effects on the mouse c...

We utilized the technique of polymerase chain reaction with oligonucleotide primers based upon the nucleotide sequence of the canine H2 histamine receptor gene which we recently isolated to clone its human homologue. Transfection of a construct of this gene in Colo-320 DM cells led to the expression of a receptor that bound to [methyl-3H] tiotidine and was linked to 3',5'cyclic adenosine monoph...

Background: Radioprotective capability of histamine H2 receptor antagonists have been shown in several in vivo studies mainly using animal models. However, to verify the effectiveness of these agents in clinical applications, studies should be performed on human cells. In the present study radioprotective properties of these agents was examined in vitro on human lymphocytes using metaphase anal...

background: radioprotective capability of histamine h2 receptor antagonists have been shown in several in vivo studies mainly using animal models. however, to verify the effectiveness of these agents in clinical applications, studies should be performed on human cells. in the present study radioprotective properties of these agents was examined in vitro on human lymphocytes using metaphase anal...

We investigated roles for substance P (SP), gastrin-releasing peptide (GRP), and glutamate in the spinal neurotransmission of histamine-dependent and -independent itch. In anesthetized mice, responses of single superficial dorsal horn neurons to intradermal (i.d.) injection of chloroquine were partially reduced by spinal application of the α-amino-3-hydroxy-5-methyl-4-isoxazole proprionate acid...

Since 2000, when the histamine H4 receptor (H4R) was cloned, it has constituted an interesting target for drug development. Pharmacological studies suggest the potential utility of histamine H4R antagonists/inverse agonists in the treatment of inflammatory diseases, e.g. allergic rhinitis, asthma, atopic dermatitis, colitis, or pruritus. The first H4R ligands were non-selective compounds, but i...

Itching of ocular allergy is alleviated but not completely relieved by H(1) histamine receptor antagonists, suggesting that histamine is not the sole itch mediator in ocular allergy. We investigated whether leukotriene B(4) (LTB(4)), a mediator of cutaneous itch, is involved in the itch of ocular allergy in mice. Mice were immunized by the repeated subcutaneous injections of ragweed pollen and ...

The interaction between smoking and the effect of histamine H2-antagonists on intragastric acidity was examined in a double blind double dummy placebo controlled study. Healthy volunteers, 11 smokers and 10 non-smokers, were given, on four separate days at least one week apart, either placebo or cimetidine 800 mg nocte or ranitidine 2 X 150 mg per day or ranitidine 300 mg nocte. Tablets were ta...

Rheumatoid arthritis is a widespread autoimmune disease. In the murine K/B×N arthritis model, anti-GPI (anti-glucose 6-phosphate isomerase) antibodies lead to the formation of immune complexes. In the course of pathogenesis, these complexes activate the immune system and induce degranulation of mast cells, which are essential in this model of rheumatoid arthritis. A major mediator in mast cell ...

BACKGROUND Prior studies suggest that histamines may modulate the development of colorectal neoplasia. AIM To assess whether histamine receptor antagonist use was associated with adenoma formation. METHODS Patients (n = 2366) were drawn from three adenoma chemoprevention trials. All underwent baseline colonoscopy with removal of adenoma(s) and were deemed free of remaining lesions; they wer...