THE EFFECT OF ALPHA-TRINOSITOL (D-MYO-INOSITOL 1,2,6-TRISPHOSPHATE) ON FORMALIN-EVOKED SPINAL AMINO-ACID AND PROSTAGLANDIN E(2) LEVELS

The effect of the inositol trisphosphate analog alpha-trinositol on no xious-evoked behavior, amino acid and prostaglandin E(2) (PGE(2)) rele ase was examined in unanesthetized rats using intrathecal microdialysi s probes. Subcutaneous injection of 50 mu l 5% formalin solution produ ced two phases of pain-like behavior and significant elevation of glut amate, aspartate, glycine, taurine and serine during phase 1. PGE(2) c oncentrations were increased during both phases 1 and 2. Intraperitone al delivery of 300 mg/kg alpha-trinositol significantly suppressed bot h phases 1 and 2 of formalin-induced behavior and the associated eleva tion of amino acids and PGE(2). These data demonstrate that the antino ciceptive effect of alpha-trinositol corresponds to suppression of nox ious-evoked release of amino acids and PGE(2) from the spinal cord.