The contributions of histamine (H1 or H2) receptor-mediated responses and, therefore, the effects of histamine blocking agents are unclear with regard to regulation of proximal epicardial and distal resistance coronary arteries. This study was designed to evaluate the effects of selective H1- and H2-receptor antagonists on epicardial and resistance vessels in the closed chest dog model. Histami...

Nerve growth factor (NGF) as an autocrine or paracrine growth factor plays a critical role in the pathogenesis and progression of human pancreatic cancer. NGF is synthesized as a proform (proNGF) that, when cleaved, releases mature ligand (mNGF). proNGF and mNGF bind to high-affinity tyrosine kinase receptor A (TrkA) and low-affinity receptor p75 to different extents. Histamine is a potent stim...

Histamine is a key mediator in allergic diseases, where it exerts most of its effects through the H1 receptor and to a less extent the H2 receptor. H1antihistamines provide rapid relief of many of the allergic symptoms and are considered the main stay of treatment of allergic rhinoconjunctivitis and urticaria. H1 antihistamines comprise first generation (old) and second generation (new) H 1 ant...

BACKGROUND Histamine drives pruritus in allergic skin diseases which clinically constitutes a most disruptive symptom. Skin pathology in allergic skin diseases is crucially influenced by different T-helper subsets. However, the contribution of different histamine-receptors to T-helper cell dependent skin pathology has not been definitively answered. Models which can specifically address the fun...

objective: crocin and safranal, as the major constituents of saffron, have many biological activities. this study investigated the effects of crocin and safranal on yawning response induced by intracerebroventricular (i.c.v.) injection of histamine in rats. materials and methods: in ketamine/xylazine-anesthetized rats, a guide cannula was implanted in the right ventricle of the brain and yawnin...

At there ambient air temperature range, the rectal temperature changes following infusion of histamine either into lateral ventricle (L.V.) or IVth ventricle (IVth V) were studied. At an ambient temperature range of 19-22 degrees C, hypothermia occurred following histamine infusion either into L.V. or IVth V. Hypothermia elicited from infusion of histamine into L.V. was prevented with pretreatm...

objective(s): the present study investigated the effects of microinjection of histamine and histamine h1, h2, and h3 receptor antagonists, chlorpheniramine, ranitidine and thioperamide, respectively into the primary somatosensory cortex (psc) on inflammatory pain.   material and methods: two stainless steel guide canulas were bilaterally implanted into the psc of anaesthetized rats. inflammator...

Few drugs have so rapidly gained an established place in modern medicine as the histamine H, receptor antagonists. As a result of the inventiveness of James Black and his colleagues, the theoretical concept of a second class of histamine receptors became a therapeutic reality. The failure of classic antihistamine drugs (more appropriately H1 receptor antagonists) to block the actions of histami...

in the present study, the effects of intracerebroventricular (icv) injections of histamine, chlorpheniramine (h1-receptor antagonist) and ranitidine (h2-receptor antagonist) were investigated on visceral nociception induced by an intraperitoneal (ip) injection of acetic acid in rats. the latency time to the beginning of the first abdominal wall contraction (the first writhe) was recorded and th...