Evaluation of cardiorespiratory parameters in rats after spinal cord trauma and treatment with NBQX, an antagonist of excitatory amino acid receptors.

2,3-Dihydroxy-6-nitro-7-sulfamoyl-benzo(f)quinoxaline (NBQX), a selective antagonist of amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA)/kainate receptors, ameliorates functional deficits and tissue loss after experimental contusive spinal cord injury (SCI). Data suggest that NBQX acts via local receptors at the injury site. However, potential systemic effects of NBQX could also modify consequences of SCI. We therefore examined effects of therapeutic doses of NBQX on cardiorespiratory parameters (CRP) including: mean arterial pressure, heart rate, respiratory rate and arterial blood gas. We found no significant effect on these CRP of either focal microinjection or intravenous administration of NBQX at doses that are therapeutic for SCI, in either uninjured rats, or rats after SCI. The results support the hypothesis that NBQX affects SCI by acting locally rather than through systemic effects and demonstrate NBQX treatment paradigms without adverse effects on CRP.