Role of endogenous enkephalins in locomotion and nociception studied with peptidase inhibitors in two inbred strains of mice (C57BL/6J and DBA/2J).
Acetorphan, a parenterally active enkephalinase inhibitor, induced dose-dependently a naloxone-reversible analgesia on the hot-plate jump test in DBA/2J (DBA2) mice but was devoid of effects in C57BL/6J (C57) mice. By contrast, acetorphan increased locomotion in both strains; however, the DBA2 strain was much more sensitive than C57 mice to the locomotor stimulant effect. The increased locomotion was antagonized by naloxone in both strains. These data suggest that endogenous enkephalins modulate nociception and locomotion in the two inbred strains differently.
Michael-Titus
A
A
Unité de Neuropsychopharmacologie expérimentale, U.A. 1170 du C.N.R.S., Faculté de Médecine & Pharmacie, Saint Etienne du Rouvray, France.
Dourmap
N
N
Caline
H
H
Costentin
J
J
Schwartz
J C
JC
D000700:Analgesics / Q000494:pharmacology*; D000818:Animals; D002552:Cerebral Ventricles / Q000187:drug effects / Q000502:physiology*; D004745:Enkephalins / Q000502:physiology*; D007276:Injections, Intraventricular; D007930:Leucine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D009043:Motor Activity / Q000187:drug effects*; D009270:Naloxone / Q000494:pharmacology; D010146:Pain / Q000503:physiopathology*; D011480:Protease Inhibitors / Q000494:pharmacology*; D012016:Reference Values; D013045:Species Specificity; D015244:Thiorphan / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology*
D000700:Analgesics; D004745:Enkephalins; D011480:Protease Inhibitors; D009270:Naloxone; C049331:racecadotril; D015244:Thiorphan; D007930:Leucine; C012211:ubenimex