Interaction of 5-bromowillardiine with non-NMDA receptors expressed in Xenopus laevis oocytes injected with chick brain mRNA.

Excitatory amino acid (EAA) receptors were studied in Xenopus laevis oocytes microinjected with 1-day-old chick brain mRNA using a two-electrode voltage clamp technique. EAA agonists could be differentially characterised according to their current/voltage (I/V) relationships; I/V plots to kainate (KA) and domoate (Dom) inwardly rectified at positive membrane potentials whereas quisqualate (QA), alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and L-glutamate (L-Glu) produced linear I/V plots. Interestingly, the non-NMDA (N-methyl-D-aspartate) agonist, 5-bromowillardiine (BrW), displayed properties similar to KA and Dom. It is proposed that BrW acts as a KA-like agonist on chick EAA receptors expressed in Xenopus oocytes.