Champion, Hunter C., Trinity J. Bivalacqua, David G. Lambert, Rasheed A. Abassi, and Philip J. Kadowitz. Analysis of vasoconstrictor responses to histamine in the hindlimb vascular bed of the rabbit. Am. J. Physiol. 277 (Regulatory Integrative Comp. Physiol. 46): R1179–R1187, 1999.—Hemodynamic responses to histamine were investigated in the anesthetized rabbit. Intravenous injections of histami...

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...

The present study was designed to investigate the effect of once daily for 7-day (subchronic treatment) dosing of histamine H3 receptor antagonists, ciproxifan (CPX) (3 mg/kg, i.p.), and clobenpropit (CBP) (15 mg/kg, i.p), including clozapine (CLZ) (3.0 mg/kg, i.p.) and chlorpromazine (CPZ) (3.0 mg/kg, i.p.), the atypical and typical antipsychotic, respectively, on MK-801(0.2 mg/kg, i.p.)-induc...

We studied the effects of histamine on human immunoglobulin (IgE) and IgG4 production. Histamine selectively enhanced IgE and IgG4 production in purified surface IgE and IgG4 negative (sIgE-sIgG4-) B cells from normal donors stimulated with interleukin (IL)-4 plus anti-CD58 or IL-13 plus anti-CD58 monoclonal antibody (mAb) without affecting production of IgG1, IgG2, IgG3, IgM, IgA1, or IgA2. In...

The possible roles of spinal histamine receptors in the regulation of the blood glucose level were studied in ICR mice. Mice were intrathecally (i.t.) treated with histamine 1 (H1) receptor agonist (2-pyridylethylamine) or antagonist (cetirizine), histamine 2 (H2) receptor agonist (dimaprit) or antagonist (ranitidine), histamine 3 (H3) receptor agonist (α-methylhistamine) or antagonist (carcini...

Previously, a novel series of 1H-4-substituted imidazole compounds were described as potent and selective histamine (HA) H3 receptor ligands (Yates et al., 1999). The present studies extend the structure-activity relationships for optimal HA H3 receptor affinity and central nervous system penetration by incorporation of a conformationally restricted cyclopropane nucleus. Moreover, the current s...

The main objective of this study was to investigate the ability of histamine receptor antagonists to modulate tryptase release from human colon mast cells induced by histamine. Enzymatically dispersed cells from human colon were challenged with histamine in the absence or presence of the histamine receptor antagonists, and the tryptase release was determined. It was found that histamine induced...

Histamine released from ECL cells elicits responses from a variety of cellular targets in the vicinity. Three sets of receptors are involved (H1, H2 and H3). Receptor occupation is promptly transduced into cellular responses. The responses, in turn, are terminated by diverse mechanisms: enzymatic inactivation, cellular uptake and desensitization at the receptor level. Under specific pathologica...

By using double in situ hybridization performed with proenkephalin and H3-receptor riboprobes on the same sections from rat brain, we show that histamine H3 receptors are expressed within striatopallidal neurons of the indirect movement pathway. The majority ( approximately 70%) of striatal enkephalin neurons express H3-receptor mRNAs. This important degree of coexpression of proenkephalin and ...

Histamine H3 receptors are present as autoreceptors on histaminergic neurons and as heteroreceptors on nonhistaminergic neurones. They control the release and synthesis of histamine and several other key neurotransmitters in the brain. H3 antagonism may be a novel approach to develop a new class of antipsychotic medications given the gathering evidence reporting therapeutic efficacy in several ...