Dissociation of analgesic and gastrointestinal effects of electroconvulsive shock-released opioids

Activation of endogenous opioid systems by electroconvulsive shock (ECS) produced naloxone-reversible thermal analgesia (52 degrees C hot plate) 5 min after ECS administration. Although opioid peptides injected intracerebroventricularly have previously been found to inhibit gastrointestinal motility, ECS treatment did not affect gastric emptying, small or large intestinal transit. These results suggest that centrally-mediated opioid analgesia and changes in gastrointestinal motility are initiated through independent mechanisms.