L-Homocysteic acid (L-HCA) is an endogenous excitatory amino acid that acts as a NMDA receptor agonist (EC50: 14 μM). L-Homocysteic acid is neurotoxic, and can be used in the research of neurological disorders[1][2][3].
L-Homocysteic acid activates NMDA receptor with an EC50 value of 14 μM[1].
L-Homocysteic acid (100 μM) induces large currents (1.8 nA) that is insensitive to the NMDA receptor-antagonist mixture in Purkinje cells[1].
L-Homocysteic acid (250 μM, 30 min) potently induces an acute excitotoxic reaction in ex vivo chick embryo retina[2].
L-Homocysteic acid (0-2 mM, 48 h) induces a concentration-dependent neurotoxic effect in rat primary neurons[3].
L-Homocysteic acid (intraperitoneal injection, 4-11 mmol/kg) elicits seizures in rats during early postnatal development[4].
L-Homocysteic acid (intraperitoneal injection, 100-1500 mg/kg) partially substitutes for NMDA, producing maximum values of 61-67% NMDA-lever responding at doses of 1000 and 560 mg/kg, respectively in Sprague-Dawley rats[5].
| Animal Model: | Male albino rats of the Wistar strain[4] |
| Dosage: | 4, 5.5, 8, 11 mM/kg |
| Administration: | Intraperitoneal injection, daily for 14 days |
| Result: | Induced flexion seizures at 4 mmol/kg. Led to intense tail flicking, pivoting, and locomotion. Decreased ECoG (electrocorticograms) activity for 5-9 min. |
[1]. M Yuzaki, et al. Characterization of L-homocysteate-induced currents in Purkinje cells from wild-type and NMDA receptor knockout mice. J Neurophysiol . 1999 Nov;82(5):2820-6.
[2]. J W Olney, et al. L-homocysteic acid: an endogenous excitotoxic ligand of the NMDA receptor. Brain Res Bull. 1987 Nov;19(5):597-602.
[3]. B Lockhart, et al. Inhibition of L-homocysteic acid and buthionine sulphoximine-mediated neurotoxicity in rat embryonic neuronal cultures with alpha-lipoic acid enantiomers. Brain Res. 2000 Feb 14;855(2):292-7.
[4]. P Mares, et al. Convulsant action of D,L-homocysteic acid and its stereoisomers in immature rats.
[5]. Katherine L Nicholson, et al. The discriminative stimulus effects of N-methyl-D-aspartate glycine-site ligands in NMDA antagonist-trained rats. Psychopharmacology (Berl). 2009 Apr;203(2):441-51.