BACKGROUND Histamine is responsible for the wheal and flare reaction in various allergic conditions. Classical antihistamines are the drugs which block the H 1 receptors and are widely used in various allergic conditions, whereas H 2 blockers are mainly used for acid peptic disease. Although H 1 receptor-mediated actions of histamine are primarily responsible for vasodilatation, vasopermeabilit...

The pathogenic mechanism of ASA-induced urticaria/angioedema (AIU) is still poorly understood, but it has been known that histamine releasing by cutaneous mast cell activation is considered to be an important role. Considering the importance of histamine in AIU, we speculated that a genetic abnormality of histamine-related genes such as a high-affinity IgE receptor, a metabolic enzyme of histam...

The contributions of histamine (H, or Hj) 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 H,and Hj-receptor antagonists on epicardial and resistance vessels in the closed chest dog model. Histamine...

A unilateral 30-min application of anodal direct current to the promotor cortex of rabbits was repeated 10 times, and cyclic AMP accumulation in response to histamine was investigated in slices of different cortical areas. Polarization with 1.0 microA decreased the cyclic AMP accumulation in the cortical area contralateral to the polarization, by which regional dominance in cyclic AMP accumulat...

The present study suggests that newly synthesized histamine is involved in the development of some animal tumors (e.g., Lewis lung carcinoma in mice and Morris hepatoma in rats). A marked induction of histidine decarboxylase (HOC) and an in crease in the histamine concentration were observed in the tumors approximately 1 week after inoculation, and there were parallel increases in ornithine dec...

The effects of ranitidine, a new H2-receptor antagonist which does not contain an imidazole ring, and cimetidine have been determined on histamine, meal-induced gastric acid secretion, and serum gastrin levels in duodenal ulcer patients. Compared with cimetidine, ranitidine was found to be about eight times more potent an inhibitor of histamine-induced secretion and four to five times more pote...

In the 1970s, the identification of the histamine H2-receptor by Black and the subsequent development of histamine H2-receptor antagonists revolutionized our understanding and treatment of acid/peptic disorders. More recently, the identification of hydrogen-potassium-stimulated adenosine triphosphatase (H+/K(+)-ATPase) as the proton pump of the parietal cell and the recognition of the prominent...

foeniculum vulgare (fennel) has been widely used in traditional medicine for treatment of variousdiseases including pediatric colic. this study was designed to assess the antinociceptive effects of aqueousextract of f. vulgare on visceral pain and possible involvement of opioidergic, serotonergic, adrenergic andhistaminergic systems. the results of this study showed that aqueous extract of f. v...

Both the histamine H1-receptor (H1R) and H2-receptor (H2R) exhibit pronounced species selectivity in their pharmacological properties; i.e., bulky agonists possess higher potencies and efficacies at guinea pig (gp) than at the corresponding human (h) receptor isoforms. In this study, we examined the effects of N-acylated imidazolylpropylguanidines substituted with a single phenyl or cyclohexyl ...

Histamine affects pancreatic secretion, but its direct action on ion transport by pancreatic duct epithelial cells (PDEC) has not been defined. We now characterize the secretory effects of histamine on cultured, well-differentiated, and nontransformed dog PDEC. Histamine stimulated, in a concentration-dependent manner (1-100 μM), a cellular125I-efflux that was inhibited by 500 μM 5-nitro-2-(3-p...