INTERACTION OF URIDINE WITH GAMMA AMINO BUTYRIC-ACID BINDING SITES IN CEREBELLAR MEMBRANES OF THE RAT

The effect of uridine, a postulated anticonvulsant agent, on GABA receptors was investigated. Uridine inhibits [3H]GABA binding to rat cerebellar buffer-washed membranes. Pretreatment of the membranes with Triton X-100 increases the effect of uridine on GABA-binding. The Scatchard analysis reveals that both high and low affinities of GABA for its receptors are affected by 1 mM uridine, while the apparent number of binding sites remains unchanged. The ability of uridine to interact competitively with GABA binding sites, also examined by the Lineweaver-Burk analysis, suggests a possible mechanism of action of this anticonvulsant agent, thus including it among those compounds characterized by a GABAergic agonist activity.