Chromaffin allografts into arachnoid of spinal cord reduce basal pain responses in rats

Abstract

In this present study, behavioral responses to a subcutaneous formalin test for pain are evaluated in rats that previously received an allograft of adrenal chromaffin tissue into arachnoid of the dorsal spinal cord and in control animals. In the group of rats with grafts, a significant basal analgesia, reversed by the opioid antagonist naloxone, is found. These findings suggest that the grafts secrete some substance that reduces the response to painful stimulation and whose action is blocked by naloxone.