L-CYSTEINESULFINIC ACID MODULATES CARDIOVASCULAR FUNCTION IN THE PERIAQUEDUCTAL GRAY AREA OF RAT

L-Cysteinesulfinic acid (CSA) involvement in modulating periaqueductal gray (PAG) presser neurons has been evaluated in the rat. Intra-PAG C SA induced an increase in mean blood pressure partially antagonized by (2S)-alpha-ethylglutamic acid (EGA), a group II metabotropic glutamat e receptors (mGluRs) antagonist. Conversely, the NMDA antagonist, DL-A PS, or the mGluRs antagonists, (+)-MCPG, UPF523. or (RS)-alpha-methyls erine-O-phosphate (MSOP), were devoid of any activity on the CSA effec t. These data show that the excitatory amino acid CSA, probably by sti mulating an mGluR, contributes with glutamate in modulating cardiovasc ular function at the FAG matter.