(R)-(-)-α-Methylhistamine dihydrobromide 

(R)-(-)-α-Methylhistamine dihydrobromide is a potent, selective and brain-penetrant agonist of H3 histamine receptor, with a K_d of 50.3 nM^[1][2]. (R)-(-)-α-Methylhistamine dihydrobromide can enhance memory retention, attenuates memory impairment in rats^[3][4][5].

(R)-(-)-α-Methylhistamine dihydrobromide is an H3-agonist that is >10 times as potent as histamine (HA). Its selectivity toward H3-receptors is >1000 times as high as that of HA. (R)-(-)-α-Methylhistamine dihydrobromide has only weak affinities for H1 and H2 receptor with a pK_i=4.8 and <3.5, repectively. (R)-(-)-α-Methylhistamine dihydrobromide displays >200-fold selectivity over H4 receptors^[1][2][3].

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

Pretreatment with (R)-(-)-α-Methylhistamine dihydrobromide (RAMH; 10 mg/kg; i.p.; 60 min before training) reverses Propofol‐induced (25 mg/kg; i.p.; 30 min before training) memory retention^[5].
(R)-(-)-α-Methylhistamine dihydrochloride (6.3 mg/kg; i.p.) significantly decreases the steady-state t-MH level in the mouse brain, whereas these compounds produced no significant changes in the HA level^[3].

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

287.00

C₆H₁₃Br₂N₃

868698-49-1

Oil

Brown to reddish brown

C[C@@H](N)CC1=CN=CN1.Br.Br

Room temperature in continental US; may vary elsewhere.

4°C, protect from light, stored under nitrogen

*In solvent : -80°C, 6 months; -20°C, 1 month (protect from light, stored under nitrogen)

• [1]. Arrang JM, et al. Highly potent and selective ligands for histamine H3-receptors. Nature. 1987 May 14-20;327(6118):117-23.  [Content Brief]

  [2]. Mohammad Shahid, et al. Histamine, Histamine Receptors, and their Role in Immunomodulation: An Updated Systematic Review. The Open Immunology Journal, 2009, 2, 9-41.

  [3]. Oishi R, et al. Effects of the histamine H3-agonist (R)-alpha-methylhistamine and the antagonist thioperamideon histamine metabolism in the mouse and rat brain. J Neurochem. 1989 May;52(5):1388-92.  [Content Brief]

  [4]. Yamasaki S, et al. The disposition of (R)-alpha-methylhistamine, a histamine H3-receptor agonist, in rats. J Pharm Pharmacol. 1994 May;46(5):371-4.  [Content Brief]

  [5]. Li WW, et al. (R)-alpha-methylhistamine suppresses inhibitory neurotransmission in hippocampal CA1 pyramidal neurons counteracting propofol-induced amnesia in rats. CNS Neurosci Ther. 2014 Sep;20(9):851-9.  [Content Brief]