PRESSOR RESPONSES TO STIMULATION OF NON-NMDA RECEPTORS IN THE SUPERFICIAL LAMINAE OF THE CAT SPINAL-CORD

Microinjection of L-glutamate (109 mM; 12-18 nl) or AMPA (150-300 mu M; 12 nl) into the superficial laminae of the L(7) dorsal horn of decerebrate or chloralose anesthetized cats significantly increased mean arterial pressure. In contrast, microinjection of NMDA (300 mu M; 12 nl) had no effect on mean arterial pressure. The presser response to L-glutamate microinjection was blocked by prior microinjection of CNQX, an antagonist to non-NMDA receptors, but not by AP-5, an antagonist to NMDA receptors. We conclude that stimulation of non-NMDA receptors in the superficial laminae of the lumbar dorsal horn increases arterial blood pressure.