Opioid mu-deficient CXBK mouse and the role of mu 1-receptors in electrically induced convulsions.
Studies were made on the role of mu 1-receptors on electrically induced convulsions in mice. A relatively selective mu 1-agonist, DAGO ([D-Ala2-N-methyl-Phe4-Gly-ol]-enkephalin) decreased the durations of tonic and clonic convulsions in C57BL/6 mice, but not in opioid mu-deficient CXBK mice, indicating that the activation of mu 1-receptors had an anticonvulsive effect on these convulsions in mice. The selective mu 1-antagonists naloxonazine and naltrexonazine promoted the clonic phase of electrically induced convulsion in C57BL/6 mice. Moreover, the duration of the clonic phase was longer in mu-deficient CXBK mice than in C57BL/6 mice. These data for CXBK mice confirmed, at least some proconvulsant effects of mu 1-antagonists in C57BL/6 mice. Thus, blockade of mu 1-receptors has a proconvulsant effect, and mu 1-receptors have at least some protective role against electrically induced convulsions.
Yokoyama
H
H
Department of Pharmacology I, Tohoku University School of Medicine, Sendai, Japan.
Onodera
K
K
Suzuki
T
T
Iinuma
K
K
Watanabe
T
T
D000818:Animals; D004597:Electroshock; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; D004745:Enkephalins / Q000494:pharmacology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008815:Mice, Inbred Strains; D009020:Morphine / Q000494:pharmacology; D017450:Receptors, Opioid, mu / Q000187:drug effects / Q000502:physiology*; D012640:Seizures / Q000503:physiopathology*
D004745:Enkephalins; D017450:Receptors, Opioid, mu; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; D009020:Morphine