Histamine is considered one of the important mediators of immediate hypersensitivity and inflammation, and acts via G protein-coupled receptors. Here, we report that histamine may affect antigen receptor-mediated immune responses of T and B cells via a signal(s) from histamine H1 receptors (H1Rs). Histamine exhibited enhancing effects on the in vitro proliferative responses of anti-CD3epsilon- ...

1. When isolated perfused lungs from normal and ovalbumin sensitized guinea-pigs were challenged with histamine and 2-methylhistamine (agonists for H1-receptor), a release of thromboxane A2-like substance was observed. The effect of histamine on production of thromboxane A2 (TXA2) in sensitized lungs, was more pronounced than in normal lungs (P less than 0.01). 2. Specific activation of histami...

The superior vestibular nucleus (SVN), which holds a key position in vestibulo-ocular reflexes and nystagmus, receives direct hypothalamic histaminergic innervations. By using rat brainstem slice preparations and extracellular unitary recordings, we investigated the effect of histamine on SVN neurons and the underlying receptor mechanisms. Bath application of histamine evoked an excitatory resp...

A novel histamine receptor subtype, histamine H(3) receptor, mediates inhibition of peripheral autonomic neurotransmission. The present study was designed to examine vascular effects of histamine H(3) receptor by using a selective histamine H(3) receptor agonist, R-(-)-alpha methylhistamine (alpha-methylhistamine), in rat mesenteric resistance arteries. The isolated mesenteric vascular beds wer...

Histamine is an inflammatory mediator present in mast cells, which are abundant in the wall of the gallbladder. We examined the electrical properties of gallbladder smooth muscle and nerve associated with histamine-induced changes in gallbladder tone. Recordings were made from gallbladder smooth muscle and neurons, and responses to histamine and receptor subtype-specific compounds were tested. ...

MAST-CELL MEDIATORS, including histamine, exert a variety of pharmacological effects, which can be explained by assuming two kinds of receptors, designated Hi and H2 (Rocklin et al., 1979). H2 receptors have been shown on e.g. T lymphocytes, their function being suppressed by histamine. In two recent papers (Osband et al., 1981; Gifford et al., 1981) cimetidine, an H2receptor antagonist, was sh...

A key role for histamine in the physiological control of gastric acid secretion was established with the advent of the histamine H2-receptor antagonists which have in vivo been shown to inhibit virtually all forms of basal and stimulated secretion.' These data can be seen to support the common mediator hypothesis championed in the last three decades by Code2 3 and which states that secretory st...

A key role for histamine in the physiological control of gastric acid secretion was established with the advent of the histamine H2-receptor antagonists which have in vivo been shown to inhibit virtually all forms of basal and stimulated secretion.' These data can be seen to support the common mediator hypothesis championed in the last three decades by Code2 3 and which states that secretory st...

A key role for histamine in the physiological control of gastric acid secretion was established with the advent of the histamine H2-receptor antagonists which have in vivo been shown to inhibit virtually all forms of basal and stimulated secretion.' These data can be seen to support the common mediator hypothesis championed in the last three decades by Code2 3 and which states that secretory st...

A key role for histamine in the physiological control of gastric acid secretion was established with the advent of the histamine H2-receptor antagonists which have in vivo been shown to inhibit virtually all forms of basal and stimulated secretion.' These data can be seen to support the common mediator hypothesis championed in the last three decades by Code2 3 and which states that secretory st...