INHIBITION BY THE TETRAMINE DISULPHIDE, BENEXTRAMINE, OF CARDIAC CHRONOTROPIC HISTAMINE H2-RECEPTOR-MEDIATED EFFECTS

Release of histamine by H2-receptor antagonists?

[Structural analysis of the histamine H2 receptor].

In gastric parietal cells the histamine H2 receptor is involved in gastric acid secretion. Molecular cloning of the cDNA for the histamine H2 receptor has revealed that the receptor is a member of the G-protein coupled receptor family. We expressed histamine H2 receptors in CHO cells, COS7 cells, and Sf9 cells to analyze N-glycosylation, palmitoylation, and desensitization of the H2 receptor, w...

Histamine H2 receptor trafficking: role of arrestin, dynamin, and clathrin in histamine H2 receptor internalization.

Agonist-induced internalization of G protein-coupled receptors (GPCRs) has been implicated in receptor desensitization, resensitization, and down-regulation. In the present study, we sought to establish whether the histamine H2 receptor (H2r) agonist amthamine, besides promoting receptor desensitization, induced H2r internalization. We further studied the mechanisms involved and its potential r...

Inhibition of H2 histamine receptor-mediated cation channel opening by protein kinase C in human promyelocytic cells.

Histamine, through H(2) receptors, triggers a prominent rise in intracellular free Ca(2+) concentration ([Ca(2+)](i)) in addition to an elevation of cAMP level in HL-60 promyelocytes. Here we show that the histamine-induced [Ca(2+)](i) rise was due to influx of Ca(2+) from the extracellular space, probably through nonselective cation channels, as incubation of the cells with SKF 96365 abolished...

Chronotropic and dromotropic effects of histamine on the canine heart.

The actions of 2-methylhistamine (H1 agonists), 4-methylhistamine (H2 agonist), and histamine were studied by selective perfusion of the sinus node artery and atrioventricular node artery in 75 dogs anesthetized with pentobarbital sodium. 2-Methylhistamine and histamine had variable and inconsistent effects on the sinus rate. 4-Methylhistamine (100 microgram/ml) produced acceleration of the sin...