NEUROACTIVE PROPERTIES OF PHOSPHONIC AMINO-ACIDS

1. Several phosphonic analogues of excitatory and inhibitory ω-carboxylic amino acids were applied by microiontophoresis to rat cerebral and cerebellar neurones. We here show that ω-phosphonic amino acids are able to interact with either excitatory or inhibitory post-synaptic receptors of ω-carboxylic amino acids. 2. The excitatory properties of the glutamate molecule are weakened after replacement of the α-carboxylic group by a phosphonic group (leading to dl-4-amino-4-phosphonobutyrate and dl-1-amino-1, 3-propyldiphosphonate). However dl-2-amino-4-phosphonobutyrate did not antagonize the excitatory effect of glutamate. 3. The classic antagonists of GABA, bicuculline methochloride and picrotoxine, were not able to reverse the inhibition induced by the phosphonic analogue, 3-aminopropylphosphonic acid. © 1979.