An adrenal-mediated, naloxone-reversible increase in reaction time in the tail-flick test following intrathecal administration of substance p at the lower thoracic spinal level in the rat

We have shown previously that intrathecal administration of substance P to the lower thoracic vertebral level increases sympathetic output and increases the adrenal output of catecholamines. As opioid peptides are co-released with catecholamines from the adrenal medullae, experiments were done to determine whether the intrathecal administration of substance P to the eighth thoracic vertebral level would alter reaction time in the tail-flick …