Overview
- Bushell, T.J. et al. (1996) Br. J. Pharmacol. 117, 1457.
- Thomsen, C. (1997) Gen. Pharmacol. 29, 151.
Alomone Labs L-AP4 inhibits specific binding of L-Glutamic acid to rat brain glutamate receptors.Percent inhibition of specific binding of 3.75 nM [3H]-L-Glutamic acid to membranes from whole rat brain (except cerebellum) was plotted against concentrations of L-AP4 (#L-150), (green circles) and of L-Glutamic acid (assay standard, black squares) and used to calculate IC50 and Ki values for L-AP4 (IC50 ≈ 4.49 µM, and Ki ≈ 4.43 µM).
L-AP4 is a synthetic, potent and selective agonist of group III metabotropic glutamate receptors (mGluR4 and mGluR6 through mGluR8). L-AP4 also depresses basal synaptic transmission in rat hippocampal slices with an IC50 of 3 µM in a dose dependent manner. Maximum depression of 74% is obtained at a concentration of 100 µM L-AP4. A concentration of 10 µM L-AP4 induces a depression of 59% and when the mGluR antagonist MCCG is added it shows little or no effect. In contrary, the mGluR antagonists MPPG and MTPG are effective L-AP4 antagonists1.
L-AP4-sensitive neuronal glutamatergic pathways include synapses of the mossy-fiber/ CA3 projection synapses of pyramidal cell projecting from the lateral olfactory tract to the pyriform cortex and synaptic contacts in the basolateral amygdala. It has also been suggested that L-AP4 sensitive receptors are important for memory and learning and might be implicated in the pathogenesis of Alzheimer’s disease2.
