In human aortic smooth muscle cells, prostaglandin E2 (PGE2) stimulates adenylyl cyclase (AC) and attenuates the increase in intracellular free Ca concentration evoked by activation of histamine H1 receptors. The mechanisms are not resolved. We show that cAMP mediates inhibition of histamine-evoked Ca signals by PGE2. Exchange proteins activated by cAMP were not required, but the effects were a...

Histamine covalently bound to glutaraldehyde-activated ferritin was prepared as either monomers or as small aggregates of approximately 0.05 to 0.15 micrometer Diam, suitable for electron microscopic detection of histamine cellular binding sites. The histamine-ferritin conjugates (MF) maintain the histamine capability to induce the opening of endothelial junctions in venules. To investigate the...

Treatment with second generation antipsychotics (SGAs), notably olanzapine and clozapine, causes severe obesity side effects. Antagonism of histamine H1 receptors has been identified as a main cause of SGA-induced obesity, but the molecular mechanisms associated with this antagonism in different stages of SGA-induced weight gain remain unclear. This review aims to explore the potential role of ...

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...

Histamine is not only a crucial cytokine in the periphery but also an important neurotransmitter and neuromodulator in the brain. It is known to act on metabotropic H1-H4 receptors, but the existence of directly histamine-gated chloride channels in mammals has been suspected for many years. However, the molecular basis of such mammalian channels remained elusive, whereas in invertebrates, genes...

Helical strips of human coronary arteries contracted in response to histamine concentration dependently, they relaxed with low concentrations and contracted with high concentrations. Treatment with cimetidine potentiated contraction in the strips with intact and damaged endothelium to a similar extent and attenuated relaxation. Removal of endothelium abolished relaxation and potentiated contrac...

e have known about histamine receptors in the heart for any years (1). The human H1and H2-histamine recepors were cloned and characterized in the early 1990s (2,3), ollowed closely by the human H3and H4-histamine eceptors several years later (4,5). Histamine is a natural ody constituent that is found throughout the body, espeially the central nervous system, mast cells, gastric mucosa arietal c...

The inhibitory effects of aqueous-ethanolic extracts of Crocus sativus (Iridaceae), on histamine (H1) receptors was examined on tracheal chains of guinea pigs. The effects of three concentrations of aqueous-ethanolic extract, 10 nM chlorpheniramine, and saline on histamine (H1) receptors were tested on three groups of guinea pig tracheal chains as follows; incubated trachea with: 1) indomethaci...