Disease relevance of 2-Methylhistamine

• There also appears to be predominance of H1 receptors mediating venous hypertension and respiratory apnoea to large doses of histamine and 2-methylhistamine [1].

High impact information on 2-Methylhistamine

• The uptake was completely blocked by desmethylimipramine (Ki = 2.5 microM) and partially by the histamine agonists and histamine-N-methyltransferase blockers 4-methylhistamine and 2-methylhistamine (I30 values obtained were 2 microM and 5 microM) [2].
• 2. Doses of histamine and 2-methylhistamine which altered body temperature when given centrally were ineffective when infused or injected I.V. 3 [3].
• A modelling study has been carried out, investigating the binding of histamine (Hist), 2-methylhistamine (2-MeHist) and 2-phenylhistamine (2-PhHist) at two postulated agonistic binding sites on transmembrane domain 5 (TM5) of the histamine H1-receptor [4].
• In HL-60 cells, histamine and 2-methylhistamine increased cytosolic Ca2+ concentration ([Ca2+]i) in a clemastine-sensitive manner [5].
• Larger doses of 2-methylhistamine also lower blood pressure but this may involve H2-receptors [6].

Biological context of 2-Methylhistamine

• Similar changes in the location (IC50) and slope (Hill coefficient) parameters were obtained with the H1-selective agonist 2-thiazolylethylamine in cerebellum and with 2-methylhistamine in both brain regions [7].
• Histamine as well as the H1-agonist, 2-methylhistamine, and the H2-agonist, 4-methylhistamine, induced ovulations in the isolated perfused rat ovary [8].
• The effects of mepyramine (H1-antagonist) and burimamide (H2-antagonist) were studied on histamine, 2-methylhistamine (a selective H1-agonist), 4-methylhistamine (a selective H2-agonist) and acetylcholine-induced changes in systemic arterial and central venous pressure and respiration in anaesthetized chickens [1].

Anatomical context of 2-Methylhistamine

• 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 [9].
• Both 4-methylhistamine and histamine (but not 2-methylhistamine) attenuated (P less than 0.05) the response of the sinus node to stimulation of the right stellate ganglion [9].
• However, whereas 2-methylhistamine and N alpha,N alpha-dimethylhistamine are apparently partial agonists in potentiating the adenosine-stimulated accumulation of cyclic AMP in slices of guinea-pig cerebral cortex, on tracheal spirals they are full agonists producing the same maximum contraction as histamine [10].
• The H1-histaminergic agonists 2-pyridylethylamine (2-PEA) and 2-methylhistamine relaxed potassium-constricted, perfused, rabbit middle cerebral arteries at low concentrations (3 x 10(-11) to 3 x 10(-8) M) and constricted them at high concentrations (3 x 10(-7) to 3 x 10(-4) M) [11].
• Superfusion of the hypothalamus with 2-methylhistamine did not affect the pressor response [12].

Associations of 2-Methylhistamine with other chemical compounds

• Ferret trachea and bronchus contract to carbachol greater than 5-HT greater than bradykinin (BK) greater than PGF2alpha greater than histamine greater than 2-methylhistamine (2-MeH: a specific H1-receptor agonist) [13].
• The effect was reproduced by the H1 agonists 2-methylhistamine and 2-pyridylethylamine, but not by the H2 agonists 4-methylhistamine and dimaprit, suggesting the involvement of an H1 receptor [14].

Gene context of 2-Methylhistamine

• The effects of 2-methylhistamine, which has predominantly H1-receptor activity, were completely abolished by the prior administration of the H1-antagonist mepyramine [15].
• It was found that pretreatment with 2-methylhistamine, a histamine H1-receptor agonist, altered neither the antinociceptive effect of morphine nor the antagonistic effect of naloxone [16].
• 2-Methylhistamine, which exhibits predominantly H1-mediated actions, increased the release of prolactin [17].
• The H1 agonist 2-methylhistamine, suppresses PHA-induced proliferation of HPBL in analogous fashion to histamine [18].
• The effect of histamine was mimicked by the H1 receptor agonist, 2-methylhistamine, but not by the H2 receptor agonist, 4-methylhistamine [19].

References