Intrathecal [Met5]enkephalin antibody blocks analgesia induced by intracerebroventricular beta-endorphin but not morphine in mice.
Intrathecal (i.t.) injection of antibody directed to [Met5]enkephalin antagonized intracerebroventricularly (i.c.v.) administered beta-endorphin-induced inhibition of the tail-flick response but not the hot-plate response. [Met5]enkephalin antibody injected i.t., however, did not affect inhibition of either the tail-flick and hot-plate response induced by morphine given i.c.v. The antibodies to [Leu5]enkephalin, dynorphin A-(1-13) and beta-endorphin even at a high dose injected i.t. did not affect the inhibition induced by i.c.v. administered beta-endorphin or morphine either in the tail-flick and hot-plate test. Our results with antibodies support the results of previous studies that beta-endorphin but not morphine produces its analgesic action by selectively releasing [Met5]enkephalin.
Tseng
L L
LL
Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee.
Suh
H H
HH
D000818:Animals; D000906:Antibodies / Q000276:immunology*; D004744:Enkephalin, Methionine / Q000276:immunology*; D007276:Injections, Intraventricular; D007278:Injections, Spinal; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D009020:Morphine / Q000008:administration & dosage / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D010147:Pain Measurement; D011930:Reaction Time / Q000187:drug effects; D001615:beta-Endorphin / Q000008:administration & dosage / Q000037:antagonists & inhibitors* / Q000494:pharmacology
D000906:Antibodies; D004744:Enkephalin, Methionine; D001615:beta-Endorphin; D009020:Morphine