Release of immunoreactive [Met5]enkephalin and cholecystokinin from the spinal cord by beta-endorphin administered intraventricularly in the pentobarbital-anesthetized rat.
Beta-endorphin (4 micrograms) injected i.v.t. induced the release of immunoreactive [Met5]enkephalin and sulfated cholecystokinin octapeptide (CCK-8s) from the spinal cord in the pentobarbital-anesthetized rat. The inhibition of the tail-flick response induced by beta-endorphin given i.v.t. was antagonized by i.t. injection of CCK-8s and potentiated by i.t. administration of the antibody to CCK-8s. The findings give support to the hypothesis that endogenous CCK-8s in the spinal cord may play a negative feedback role in modulating beta-endorphin-induced antinociception.
Tseng
L F
LF
Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee 53226.
Huang
F Y
FY
D000758:Anesthesia; D000818:Animals; D002766:Cholecystokinin / Q000276:immunology / Q000378:metabolism* / Q000494:pharmacology; D004744:Enkephalin, Methionine / Q000276:immunology / Q000378:metabolism*; D007276:Injections, Intraventricular; D007278:Injections, Spinal; D008297:Male; D010147:Pain Measurement; D010424:Pentobarbital; D051381:Rats; D017207:Rats, Sprague-Dawley; D011930:Reaction Time / Q000187:drug effects; D013116:Spinal Cord / Q000187:drug effects / Q000378:metabolism*; D001615:beta-Endorphin / Q000008:administration & dosage / Q000494:pharmacology*
D004744:Enkephalin, Methionine; D001615:beta-Endorphin; D002766:Cholecystokinin; D010424:Pentobarbital